Organization of high dose chemotherapy with stem cell transplantation essentially requires EDV-support. "ONCOBASE" has been adapted into the Donauspital network on May 1, 1992. We report about the 2-year clinical experience with ONCOBASE: 1. ONCOBASE effectively supports communication between the ward, ambulance and hospital pharmacy (where all cytostatics are prepared). 2. ONCOBASE provides better surveillance concerning all therapeutic procedures including cytostatic drugs and supportive therapies. 3. ONCOBASE allows the generation of medical letters which include all drugs and supportive therapies delivered. 4. Since ONCOBASE is a database program, all informations concerning the patients are registered. These include cumulative drug doses, information on side effects, blood cell kinetics after previous therapies, kinetics of tumor markers and results of further examinations. 5. ONCOBASE permits rapid data exchange with other hospital networks using the communication data record governed by the "Arbeitskreis für EDV der deutschen Gesellschaft für Hämatoonkologie".