The German pain questionnaire (DSF) has been developed and validated by the Task force on "Standardization and Economy in Pain Management" of the German Chapter of the International Association for the Study of Pain (DGSS). The concept of the DSF is based on a bio (medical) - psycho - social pain model. The modular approach to pain assessment consists of:demographic data,pain variables (e. g. pain sites, temporal characteristics, duration, intensity),pain associated symptoms,affective and sensory qualities of pain (adjective list by Geissner, SESCopyright ),pain relieving and intensifying factors,previous pain treatment procedures,pain-related disability (Pain Disability Index by Tait et al.),depression test CES-D (Center for Epidemiological Studies Depression Test),comorbid conditions,social factors (educational level, occupation, retirement status, compensation and/or litigation status, disability for work),health related quality of life (SF-36Copyright ). Practicability and content validity were tested in some 3000 patients. Comparison with external criteria (e. g. medical and psychiatric-psychological diagnoses, physician-determined chronicity of pain) proved good content validity and excellent reliability of patients statements in the questionnaire. The great majority of patients stated that the DSF covered their pain history completely and in an orderly fashion. Difficulty to answer the questions was considered low. The German pain questionnaire is a reliable and valid instrument for recording the multidimensional experience of pain. Data from such questionnaires are indispensable for follow-up studies and internal and external quality assessments. The DSF can be ordered from the German Society for the Study of Pain (www.dgss.org) and is a core instrument of the computer program "quality assurance in pain management" (QUAST) of this society.