Four wastewater treatment plants running with sequencing batch reactor (SBR) technology have been evaluated in view of their effluent quality, treatment efficiency and energy demand. The plants are designed for approximately 5,000, 8,000, 15,000 and 25,000 population equivalents (p.e.). Although two of the plants were overloaded during the investigation time the effluent concentrations of nitrogen, especially ammonia, and phosphorus were low. The results show, that SBR plants which are designed according to German standards have additional capacities for degradation of organic matter and removal of nitrogen and phosphorus. Furthermore SBR plants with combined sewer systems are able to treat combined sewage very well. Thus SBR technology proves to be a good alternative for municipal sewage plants and can help to save investment costs.