UV irradiation as a method of disinfecting drinking, waste and feed waters is becoming more and more widespread. Besides the normally used low and medium pressure lamps, a new type has been recently developed, the microwave stimulated electrodeless lamp. This paper presents first results on drinking water disinfection using this new type of lamp. Its suitability for application could be shown in experiments with microorganisms of risk group one. Additionally, research results on the direct electrolysis of water for disinfection purposes are given. The combination of the two methods provides a promising approach to disinfection treatment of drinking water.