The practice guidelines of the German Society of Psychiatry, Psychotherapy and Nervous Diseases (DGPPN) include systematically developed and evidence-based treatment recommendations which assist clinicians and patients in making decisions about appropriate treatment for specific conditions. The intentions of practice guidelines are to improve the quality of care and the outcome of mental diseases. This paper describes the methodology behind the development of the guidelines and lists the already existing practice guidelines as well as the guidelines actually being developed. In addition, it is outlined how quality indicators may be derived from guidelines. A major aim of the German Society of Psychiatry, Psychotherapy and Nervous Diseases (DGPPN) is to assure the quality of inpatient and outpatient care of the mentally ill by developing evidence-based consensus guidelines.