From 25 to 27 Sept 1997, a workshop was organized at the Essen Medical School (Universitätsklinikum Essen), at which radiooncologists and jurists from universities and courts as well as lawyers contributed their views on mutual problems. The following topics were discussed by papers and in round table meetings: "Requirements on the patient's information", "definition of therapeutic guidelines-limits of clinical research and standard treatments", "treatment documentation", "liability of the physician for treatment faults" and "technical standard and preserve of quality". The consensual guidelines to the topics "patient's information", "therapeutic guidelines" and "liability" are presented here.