An improved user interface for a defibrillator (100) capable of being used with paddle electrodes (180) and adhesive pad electrodes (190). A shock delivery button (110) located on the defibrillator control panel delivers a shock through the pad electrodes. A second shock delivery button (210), located on the paddle electrodes, delivers a shock through the paddle electrodes. Both shock delivery buttons are configured with the same shape, operation and illumination in order to reduce user confusion.