In this summary, J. Konietzko (Mainz) stressed the exceptional position of occupational cancer, which is due to the long latent period between exposure to specific carcinogens and cancer manifestation. Obviously, this long latent period of years to decades poses problems in the search for the etiology of occupational cancer. Three methodological areas are instrumental in overcoming these problems. They include epidemiological investigations, in vitro experiments and animal experiments, which have to complement each other. A highly important area within the aetiological research is the field of syncarcinogenesis. Up to now, some research on combined effects has been done, but this field urgently needs further efforts and promotion since the threat of more than additive carcinogenic effects can be ruled out or prevented only after the necessary knowledge has been gathered from properly conducted basic research. Within the discussion of occupational cancer, three areas have to be discriminated; they relate to cancer as an occupational disease, as a problem within the insurance laws, and as a risk that requires preventive measures. Its acknowledgement as an occupational disease is based on strict legal preconditions that limit any generosity. Such a procedure is too reserved, however, as far as preventive measures are concerned. In this area, more generous criteria are required, which do not only result from scientific procedures. Prevention is subject to a clear ranking; primary prevention, i.e. the elimination of carcinogens from the workplace, has priority. If the elimination of occupational hazards is impossible, a quantitative risk assessment that takes account of synergistic carcinogenic effects can help to set priorities. The impossibility of a complete primary prevention necessitates secondary and tertiary prevention, which correspond to early diagnosis and follow-up management of occupational cancer. Each of these areas needs continued attention.