diff --git a/doc.go b/doc.go
index c5201ad..3ca1637 100644
--- a/doc.go
+++ b/doc.go
@@ -15,41 +15,62 @@
    madb [flags] <command>
 
 The madb commands are:
-   exec        Run the provided adb command on all the specified devices
+   exec        Run the provided adb command on all devices and emulators
                concurrently
    name        Manage device nicknames
    help        Display help for commands or topics
 
+The madb flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 The global flags are:
  -metadata=<just specify -metadata to activate>
    Displays metadata for the program and exits.
  -time=false
    Dump timing information to stderr before exiting the program.
 
-Madb exec - Run the provided adb command on all the specified devices concurrently
+Madb exec - Run the provided adb command on all devices and emulators concurrently
 
-Runs the provided adb command on all the specified devices concurrently.
+Runs the provided adb command on all devices and emulators concurrently.
 
 For example, the following line:
 
     madb -a exec push ./foo.txt /sdcard/foo.txt
 
 copies the ./foo.txt file to /sdcard/foo.txt for all the currently connected
-Android devices (specified by -a flag).
+Android devices.
 
 To see the list of available adb commands, type 'adb help'.
 
 Usage:
    madb exec [flags] <command>
 
-<command> is a normal adb command, which will be executed on all the specified
-devices.
+<command> is a normal adb command, which will be executed on all devices and
+emulators.
+
+The madb exec flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
 
 Madb name - Manage device nicknames
 
 Manages device nicknames, which are meant to be more human-friendly compared to
 the device serials provided by adb tool.
 
+NOTE: Device specifier flags (-d, -e, -n) are ignored in all 'madb name'
+commands.
+
 Usage:
    madb name [flags] <command>
 
@@ -59,6 +80,15 @@
    list        List all the existing nicknames.
    clear-all   Clear all the existing nicknames.
 
+The madb name flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 Madb name set
 
 Sets a human-friendly nickname that can be used when specifying the device in
@@ -92,6 +122,15 @@
 device specifier (e.g., 'usb:3-3.4.2') obtained from 'adb devices -l' command
 <nickname> is an alpha-numeric string with no special characters or spaces.
 
+The madb name set flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 Madb name unset
 
 Unsets a nickname assigned by the 'madb name set' command. Either the device
@@ -103,6 +142,15 @@
 There should be only one argument, which is either the device serial or the
 nickname.
 
+The madb name unset flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 Madb name list
 
 Lists all the currently stored nicknames of device serials.
@@ -110,6 +158,15 @@
 Usage:
    madb name list [flags]
 
+The madb name list flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 Madb name clear-all
 
 Clears all the currently stored nicknames of device serials.
@@ -117,6 +174,15 @@
 Usage:
    madb name clear-all [flags]
 
+The madb name clear-all flags are:
+ -d=false
+   Restrict the command to only run on real devices.
+ -e=false
+   Restrict the command to only run on emulators.
+ -n=
+   Comma-separated device serials, qualifiers, or nicknames (set by 'madb
+   name').  Command will be run only on specified devices.
+
 Madb help - Display help for commands or topics
 
 Help with no args displays the usage of the parent command.
diff --git a/exec.go b/exec.go
index 71470c4..7b5307f 100644
--- a/exec.go
+++ b/exec.go
@@ -16,21 +16,21 @@
 var cmdMadbExec = &cmdline.Command{
 	Runner: cmdline.RunnerFunc(runMadbExec),
 	Name:   "exec",
-	Short:  "Run the provided adb command on all the specified devices concurrently",
+	Short:  "Run the provided adb command on all devices and emulators concurrently",
 	Long: `
-Runs the provided adb command on all the specified devices concurrently.
+Runs the provided adb command on all devices and emulators concurrently.
 
 For example, the following line:
 
     madb -a exec push ./foo.txt /sdcard/foo.txt
 
-copies the ./foo.txt file to /sdcard/foo.txt for all the currently connected Android devices (specified by -a flag).
+copies the ./foo.txt file to /sdcard/foo.txt for all the currently connected Android devices.
 
 To see the list of available adb commands, type 'adb help'.
 `,
 	ArgsName: "<command>",
 	ArgsLong: `
-<command> is a normal adb command, which will be executed on all the specified devices.
+<command> is a normal adb command, which will be executed on all devices and emulators.
 `,
 }
 
@@ -41,7 +41,7 @@
 		return err
 	}
 
-	devices, err := getDevices(getDefaultNameFilePath())
+	devices, err := getSpecifiedDevices()
 	if err != nil {
 		return err
 	}
diff --git a/madb.go b/madb.go
index 085db51..2f7efb2 100644
--- a/madb.go
+++ b/madb.go
@@ -17,6 +17,18 @@
 	"v.io/x/lib/gosh"
 )
 
+var (
+	allDevicesFlag   bool
+	allEmulatorsFlag bool
+	devicesFlag      string
+)
+
+func init() {
+	cmdMadb.Flags.BoolVar(&allDevicesFlag, "d", false, `Restrict the command to only run on real devices.`)
+	cmdMadb.Flags.BoolVar(&allEmulatorsFlag, "e", false, `Restrict the command to only run on emulators.`)
+	cmdMadb.Flags.StringVar(&devicesFlag, "n", "", `Comma-separated device serials, qualifiers, or nicknames (set by 'madb name').  Command will be run only on specified devices.`)
+}
+
 var cmdMadb = &cmdline.Command{
 	Children: []*cmdline.Command{cmdMadbExec, cmdMadbName},
 	Name:     "madb",
@@ -69,13 +81,13 @@
 }
 
 // Runs "adb devices -l" command, and parses the result to get all the device serial numbers.
-func getDevices(filename string) ([]device, error) {
+func getDevices(nicknameFile string) ([]device, error) {
 	sh := gosh.NewShell(gosh.Opts{})
 	defer sh.Cleanup()
 
 	output := sh.Cmd("adb", "devices", "-l").Stdout()
 
-	nsm, err := readNicknameSerialMap(filename)
+	nsm, err := readNicknameSerialMap(nicknameFile)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "Warning: Could not read the nickname file.")
 	}
@@ -138,3 +150,73 @@
 
 	return result, nil
 }
+
+// Gets all the devices specified by the device specifier flags.
+// Intended to be used by most of the madb sub-commands except for 'madb name'.
+func getSpecifiedDevices() ([]device, error) {
+	allDevices, err := getDevices(getDefaultNameFilePath())
+	if err != nil {
+		return nil, err
+	}
+
+	filtered := filterSpecifiedDevices(allDevices)
+
+	if len(filtered) == 0 {
+		return nil, fmt.Errorf("No devices matching the device specifiers.")
+	}
+
+	return filtered, nil
+}
+
+func filterSpecifiedDevices(devices []device) []device {
+	// If no device specifier flags are set, run on all devices and emulators.
+	if noDevicesSpecified() {
+		return devices
+	}
+
+	result := make([]device, 0, len(devices))
+
+	for _, d := range devices {
+		if shouldIncludeDevice(d) {
+			result = append(result, d)
+		}
+	}
+
+	return result
+}
+
+func noDevicesSpecified() bool {
+	return allDevicesFlag == false &&
+		allEmulatorsFlag == false &&
+		devicesFlag == ""
+}
+
+func shouldIncludeDevice(d device) bool {
+	if allDevicesFlag && d.Type == realDevice {
+		return true
+	}
+
+	if allEmulatorsFlag && d.Type == emulator {
+		return true
+	}
+
+	tokens := strings.Split(devicesFlag, ",")
+	for _, token := range tokens {
+		// Ignore empty tokens
+		if token == "" {
+			continue
+		}
+
+		if d.Serial == token || d.Nickname == token {
+			return true
+		}
+
+		for _, qualifier := range d.Qualifiers {
+			if qualifier == token {
+				return true
+			}
+		}
+	}
+
+	return false
+}
diff --git a/madb_test.go b/madb_test.go
index 2f0567e..1fbbf4b 100644
--- a/madb_test.go
+++ b/madb_test.go
@@ -116,3 +116,75 @@
 		t.Fatalf("unmatched results: got %v, want %v", got, want)
 	}
 }
+
+func TestGetSpecifiedDevices(t *testing.T) {
+	// First, define some devices (three real devices, and two emulators).
+	d1 := device{
+		Serial:     "deviceid01",
+		Type:       realDevice,
+		Qualifiers: []string{"usb:3-3.4.3", "product:bullhead", "model:Nexus_5X", "device:bullhead"},
+		Nickname:   "MyPhone",
+	}
+
+	d2 := device{
+		Serial:     "deviceid02",
+		Type:       realDevice,
+		Qualifiers: []string{"usb:3-3.4.1", "product:volantisg", "model:Nexus_9", "device:flounder_lte"},
+		Nickname:   "",
+	}
+
+	e1 := device{
+		Serial:     "emulator-5554",
+		Type:       emulator,
+		Qualifiers: []string{"product:sdk_phone_armv7", "model:sdk_phone_armv7", "device:generic"},
+		Nickname:   "ARMv7",
+	}
+
+	d3 := device{
+		Serial:     "deviceid03",
+		Type:       realDevice,
+		Qualifiers: []string{"usb:3-3.3", "product:bullhead", "model:Nexus_5X", "device:bullhead"},
+		Nickname:   "SecondPhone",
+	}
+
+	e2 := device{
+		Serial:     "emulator-5555",
+		Type:       emulator,
+		Qualifiers: []string{"product:sdk_phone_armv7", "model:sdk_phone_armv7", "device:generic"},
+		Nickname:   "",
+	}
+
+	allDevices := []device{d1, d2, e1, d3, e2}
+
+	type deviceFlags struct {
+		allDevices   bool
+		allEmulators bool
+		devices      string
+	}
+
+	type testCase struct {
+		flags deviceFlags
+		want  []device
+	}
+
+	testCases := []testCase{
+		testCase{deviceFlags{false, false, ""}, allDevices},                        // Nothing is specified
+		testCase{deviceFlags{true, true, ""}, allDevices},                          // Both -d and -e are specified
+		testCase{deviceFlags{true, false, ""}, []device{d1, d2, d3}},               // Only -d is specified
+		testCase{deviceFlags{false, true, ""}, []device{e1, e2}},                   // Only -e is specified
+		testCase{deviceFlags{false, false, "device:bullhead"}, []device{d1, d3}},   // Device qualifier
+		testCase{deviceFlags{false, false, "ARMv7,SecondPhone"}, []device{e1, d3}}, // Nicknames
+		testCase{deviceFlags{true, false, "ARMv7"}, []device{d1, d2, e1, d3}},      // Combinations
+		testCase{deviceFlags{false, true, "model:Nexus_9"}, []device{d2, e1, e2}},  // Combinations
+	}
+
+	for i, testCase := range testCases {
+		allDevicesFlag = testCase.flags.allDevices
+		allEmulatorsFlag = testCase.flags.allEmulators
+		devicesFlag = testCase.flags.devices
+
+		if got := filterSpecifiedDevices(allDevices); !reflect.DeepEqual(got, testCase.want) {
+			t.Fatalf("unmatched results for testCases[%v]: got %v, want %v", i, got, testCase.want)
+		}
+	}
+}
diff --git a/name.go b/name.go
index 6d1d5d7..c8773af 100644
--- a/name.go
+++ b/name.go
@@ -22,6 +22,8 @@
 	Long: `
 Manages device nicknames, which are meant to be more human-friendly compared to
 the device serials provided by adb tool.
+
+NOTE: Device specifier flags (-d, -e, -n) are ignored in all 'madb name' commands.
 `,
 }