Estimates of the recent and future burden of occupational diseases indicate that occupational cancer is still a major problem and will remain so in the future as a result of exposure of workers to carcinogens. This report provides an overview of assessment tools for the exposure to cancer risk factors and looks into relevant occupational factors: chemical, physical and biological exposures, as well as other possibly carcinogenic working environment conditions (such as shift and night work). It also examines opportunities to identify new causes or promoters of cancer, and evaluates existing sources of information, to identify major knowledge gaps and describe some new approaches needed to assess and prevent occupational cancer risks. It also describes occupational cancer prevention measures at European, national and workplace levels and makes recommendations for filling in gaps in relevant knowledge needed to prevent effectively future risks of occupational cancer. The issue of vulnerable groups of workers (for example women, young workers, workers experiencing high exposure to carcinogens, workers in precarious conditions) is also addressed.