At the University Hospital Freiburg (1,927 beds; 53,000 inpatients/year), we developed and ran a Medical Information, Retrieval, and Archives System (MIRA) by integrating the Minimum Basic Data Set into the self developed patient administration system and all the other parts of our hospital information system. Especially for the physicians, MIRA offers access to basic medical data of all patients treated in all medical departments and separate buildings since 1986. MIRA is mainly used in cases of readmission and for scientific and managerial purposes. The privacy controlled access to the central patient data bases (records of 450,000 patients) of MIRA is possible via 610 online PCs and dialog terminals. Because of the many easy-to-use standard functions and special extensions for different clinical departments, MIRA became one of the best accepted edp systems for physicians, nurses and administrators.