diff --git a/files/rcongui b/files/rcongui
new file mode 100644
index 0000000..1d39f3e
--- /dev/null
+++ b/files/rcongui
@@ -0,0 +1,8 @@
+#! /usr/bin/env python3
+"""An RCON client."""
+
+from rcon.gui import main
+
+
+if __name__ == '__main__':
+    main()
diff --git a/rcon/gui.py b/rcon/gui.py
new file mode 100644
index 0000000..ab837ae
--- /dev/null
+++ b/rcon/gui.py
@@ -0,0 +1,110 @@
+"""GTK based GUI."""
+
+from socket import timeout
+
+from gi import require_version
+require_version('Gtk', '3.0')
+# pylint: disable=C0413
+from gi.repository import Gtk
+
+from rcon.exceptions import RequestIdMismatch, WrongPassword
+from rcon.proto import Client
+
+
+__all__ = ['main']
+
+
+class GUI(Gtk.Window):
+    """A GTK based GUI for RCON."""
+
+    def __init__(self):
+        """Initializes the GUI."""
+        super().__init__(title='RCON GUI')
+
+        self.set_position(Gtk.WindowPosition.CENTER)
+
+        self.grid = Gtk.Grid()
+        self.add(self.grid)
+
+        self.host = Gtk.Entry()
+        self.host.set_placeholder_text('Host')
+        self.grid.attach(self.host, 0, 0, 1, 1)
+
+        self.port = Gtk.Entry()
+        self.port.set_placeholder_text('Port')
+        self.grid.attach(self.port, 1, 0, 1, 1)
+
+        self.passwd = Gtk.Entry()
+        self.passwd.set_placeholder_text('Password')
+        self.grid.attach(self.passwd, 2, 0, 1, 1)
+
+        self.command = Gtk.Entry()
+        self.command.set_placeholder_text('Command')
+        self.grid.attach(self.command, 0, 1, 2, 1)
+
+        self.button = Gtk.Button(label='Run')
+        self.button.connect('clicked', self.on_button_clicked)
+        self.grid.attach(self.button, 2, 1, 1, 1)
+
+        self.result = Gtk.Entry()
+        self.result.set_placeholder_text('Result')
+        self.grid.attach(self.result, 0, 2, 3, 1)
+
+    def show_error(self, message: str):
+        """Shows an error message."""
+        message_dialog = Gtk.MessageDialog(
+            transient_for=self,
+            message_type=Gtk.MessageType.ERROR,
+            buttons=Gtk.ButtonsType.OK,
+            text=message)
+        message_dialog.run()
+        message_dialog.destroy()
+
+    def on_button_clicked(self, _):
+        """Runs the client."""
+        if not (host := self.host.get_text()):  # pylint: disable=C0325
+            self.show_error('No host specified.')
+            return
+
+        if not (port := self.port.get_text()):  # pylint: disable=C0325
+            self.show_error('No port specified.')
+            return
+
+        try:
+            port = int(port)
+        except ValueError:
+            self.show_error(f'Invalid port: {port}')
+            return
+
+        passwd = self.passwd.get_text()
+
+        if not (command := self.command.get_text()):    # pylint: disable=C0325
+            self.show_error('No command entered.')
+            return
+
+        try:
+            with Client(host, port, passwd=passwd) as client:
+                result = client.run(command)
+        except ConnectionRefusedError:
+            self.show_error('Connection refused.')
+        except timeout:
+            self.show_error('Connection timed out.')
+        except RequestIdMismatch:
+            self.show_error('Request ID mismatch.')
+        except WrongPassword:
+            self.show_error('Invalid password.')
+        else:
+            self.result.set_text(result)
+
+
+def main():
+    """Starts the GUI."""
+
+    win = GUI()
+    win.connect('destroy', Gtk.main_quit)
+    win.show_all()
+    Gtk.main()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/setup.py b/setup.py
index 1bbc5f4..a0ec49c 100755
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ setup(
     author_email='mail@richard-neumann.de',
     python_requires='>=3.8',
     packages=['rcon'],
-    scripts=['files/rconclt', 'files/rconshell'],
+    scripts=['files/rcongui', 'files/rconclt', 'files/rconshell'],
     url='https://github.com/conqp/rcon',
     license='GPLv3',
     description='A RCON client library library.',