Quality assurance is the corrective action applied to any observed discrepancy between optimal and actual level of medical care requiring continuous quality control. According to the German health act "Gesundheitsreformgesetz" introduced in 1989 [46], involvement in quality assurance is mandatory for all health professionals. Obviously, quality assurance is of utmost importance in psychiatric practice. Quality care as defined by the degree of adherence to standards and guidelines can be measured in terms of structural, process and outcome characteristics referring to inpatient, outpatient and complementary services. To promote the implementation of practice guidelines into psychiatric care conceptual, methodological, political, financial, and organizational requirements must be taken into account.