diff --git a/README.md b/README.md
index 866b982..e4b8a45 100644
--- a/README.md
+++ b/README.md
@@ -17,11 +17,10 @@ go build
 
 ## Usage
 
-Build a Linux x86-64 ELF executable from `examples/hello`:
+Build a Linux x86-64 ELF executable from `examples/hello` and run it:
 
 ```shell
-./q build examples/hello
-./examples/hello/hello
+./q run examples/hello
 ```
 
 ## Documentation
diff --git a/src/build/errors/UnknownCLIParameter.go b/src/build/errors/UnknownCLIParameter.go
new file mode 100644
index 0000000..136864e
--- /dev/null
+++ b/src/build/errors/UnknownCLIParameter.go
@@ -0,0 +1,13 @@
+package errors
+
+import "fmt"
+
+// UnknownCLIParameter error is created when a command line parameter is not recognized.
+type UnknownCLIParameter struct {
+	Parameter string
+}
+
+// Error generates the string representation.
+func (err *UnknownCLIParameter) Error() string {
+	return fmt.Sprintf("Unknown parameter '%s'", err.Parameter)
+}
diff --git a/src/cli/Build.go b/src/cli/Build.go
index ac4066c..6b74ce6 100644
--- a/src/cli/Build.go
+++ b/src/cli/Build.go
@@ -7,10 +7,30 @@ import (
 
 	"git.akyoto.dev/cli/q/src/build"
 	"git.akyoto.dev/cli/q/src/build/config"
+	"git.akyoto.dev/cli/q/src/build/errors"
 )
 
 // Build parses the arguments and creates a build.
 func Build(args []string) int {
+	_, err := buildWithArgs(args)
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+
+		switch err.(type) {
+		case *errors.UnknownCLIParameter:
+			return 2
+
+		default:
+			return 1
+		}
+	}
+
+	return 0
+}
+
+// buildWithArgs creates a new build with the given arguments.
+func buildWithArgs(args []string) (*build.Build, error) {
 	b := build.New()
 
 	for i := 0; i < len(args); i++ {
@@ -26,8 +46,7 @@ func Build(args []string) int {
 			config.Comments = true
 		default:
 			if strings.HasPrefix(args[i], "-") {
-				fmt.Printf("Unknown parameter: %s\n", args[i])
-				return 2
+				return b, &errors.UnknownCLIParameter{Parameter: args[i]}
 			}
 
 			b.Files = append(b.Files, args[i])
@@ -38,16 +57,16 @@ func Build(args []string) int {
 		b.Files = append(b.Files, ".")
 	}
 
-	return run(b)
+	err := makeExecutable(b)
+	return b, err
 }
 
-// run starts the build by running the compiler and then writing the result to disk.
-func run(b *build.Build) int {
+// makeExecutable starts the build by running the compiler and then writing the result to disk.
+func makeExecutable(b *build.Build) error {
 	result, err := b.Run()
 
 	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		return 1
+		return err
 	}
 
 	if config.Assembler {
@@ -55,15 +74,8 @@ func run(b *build.Build) int {
 	}
 
 	if config.Dry {
-		return 0
+		return nil
 	}
 
-	err = result.Write(b.Executable())
-
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		return 1
-	}
-
-	return 0
+	return result.Write(b.Executable())
 }
diff --git a/src/cli/Help.go b/src/cli/Help.go
index b6c8f58..8d4f0ef 100644
--- a/src/cli/Help.go
+++ b/src/cli/Help.go
@@ -12,6 +12,7 @@ func Help(w io.Writer, code int) int {
     commands:
 
         build [directory | file]
+        run [directory | file]
         help
         system
 
diff --git a/src/cli/Main.go b/src/cli/Main.go
index 2b90bda..31b387b 100644
--- a/src/cli/Main.go
+++ b/src/cli/Main.go
@@ -14,6 +14,9 @@ func Main(args []string) int {
 	case "build":
 		return Build(args[1:])
 
+	case "run":
+		return Run(args[1:])
+
 	case "system":
 		return System(args[1:])
 
diff --git a/src/cli/Main_test.go b/src/cli/Main_test.go
index 6471939..4d40adb 100644
--- a/src/cli/Main_test.go
+++ b/src/cli/Main_test.go
@@ -25,6 +25,8 @@ func TestCLI(t *testing.T) {
 		{[]string{"build", "../../examples/hello", "--dry", "--verbose"}, 0},
 		{[]string{"build", "../../examples/hello/hello.q", "--dry"}, 0},
 		{[]string{"build", "../../examples/hello"}, 0},
+		{[]string{"run", "../../examples/hello", "--invalid"}, 2},
+		{[]string{"run", "../../examples/hello"}, 0},
 	}
 
 	for _, test := range tests {
diff --git a/src/cli/Run.go b/src/cli/Run.go
new file mode 100644
index 0000000..9133f36
--- /dev/null
+++ b/src/cli/Run.go
@@ -0,0 +1,46 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+
+	"git.akyoto.dev/cli/q/src/build/errors"
+)
+
+// Run builds and runs the executable.
+func Run(args []string) int {
+	b, err := buildWithArgs(args)
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+
+		switch err.(type) {
+		case *errors.UnknownCLIParameter:
+			return 2
+
+		default:
+			return 1
+		}
+	}
+
+	cmd := exec.Command(b.Executable())
+	cmd.Stdout = os.Stdout
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	err = cmd.Run()
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+
+		switch err.(type) {
+		case *exec.ExitError:
+			return 0
+
+		default:
+			return 1
+		}
+	}
+
+	return 0
+}