The central tasks of health services research include the description and analysis of health care under everyday conditions as well as the development and evaluation of new concepts. As a first step, the reality of the health services' situation should be assessed using representative data. For that, registries, claims data of health insurance funds or observational studies are suitable. To investigate specific patterns or decisions, qualitative methods are of importance. To evaluate the effectiveness of health care concepts or structures, pragmatic randomized, controlled trials are considered to provide the best evidence. In this paper we discuss these questions on the basis of treatment for patients with small renal masses. Although recent guidelines recommend nephron-sparing surgery instead of radical nephrectomy for these patients, international studies suggest that there is a significant underuse of nephron-sparing procedures. However, national data describing the situation in Germany are necessary to analyse reasons and to develop new concepts which subsequently have to be tested in randomized trials. Therefore, the aim of health services research is to create a scientific basis for continuous improvements in health care. Urology needs health services research and we should find ways to overcome barriers to improve quality of care.