ZnSe-based laser diodes grown by molecular beam epitaxy are tested under various current driving conditions. We found that the driving conditions do not influence the degradation process itself. Lifetime measurements show no dependence on the pulse width of the applied current, whereas the duty cycle has a strong influence on the lifetime. This indicates that heat is one of the driving forces of the degradation process. It is found that stable high-power pulsed operation can be maintained over a long time when the delay between the current pulses is long enough. In pulsed mode light pulses with 128 mW and in continous wave (cw)-mode an output power of more than 37 mW have been obtained.