BACKGROUND: Facts and figures about German radio-oncologic centers are scarcely available. A first glance was made possible by the accumulation of data published by the German Röntgen Society ("Abteilungen und Praxen für Strahlentherapie in der Bundesrepublik Deutschland, 1994"[4]). Detailed and up-to-date information is difficult to collect from the whole Federal Republic. Therefore, a regional data-base limited to the 6 northern German states was created in order to get correct, detailed and current facts and figures from radio-oncologic departments of this region. PATIENTS AND METHOD: Traditionally there was a close cooperation between the Röntgen Society of Northern Germany and the Society of "Niedersachsen" and "Sachsen-Anhalt". Therefore, hospital departments and free standing office-type facilities in radio-oncology from 6 states have put together a regional North German data-base. Detailed questionnaires were sent out in order to get data on heads of departments, professional staff, technical equipment, workload, diagnoses and training facilities. The collected data were distributed to all participating centers for confidential individual analysis. This paper reports the data collected. RESULTS: The survey 1995/96 had an unexpected return. Thirty-six from 38 centers in a region with 17.36 million inhabitants in 6 states (21.3% of Germany) took part. There were 73 megavolt machines and 31 afterloading facilities. Two hundred and forty physicians, 110 physicists, and 350 radiographers were working in radio-oncology; and there were 852 hospital beds specifically assigned to radio-oncology for the care of in-patients. In 1995, 32,000 patients were treated with 37,000 series, 570,000 treatment visits and 1,600,000 radiation fields. The average patient got 1.2 series, 18 treatment visits and 50 fields. Equipment-wise, an average department runs a mean of 2 megavolt machines and 1 afterloading facility. The corresponding data for 1 megavolt machine were 3.5 physicians, 1.6 physicists, 5 radiographers and 13 hospital beds. There was 1 machine for 240,000 inhabitants. The average workload of a megavolt machine was 439 patients a year with 513 series, 7,813 treatment visits and 21,845 radiation fields. CONCLUSIONS: A regional data-base for radio-oncology is being described. It is demonstrated that it is possible to get detailed and current data by this method. It provides transparent data on equipment, personnel and workload in radio-oncology. It should set an example for other regions to collect their data in the same fashion, and then compile all such data for the whole country to identify and correct potential deficiencies for improvement of care.