This paper reviews the available literature regarding the work environment in pulp and paper mills and the risk for malignant diseases. An increased risk for lung cancer among pulp and paper mill workers has been reported. Most studies are inconclusive with regard to considerations of etiologic agents. However, maintenance workers seem to be at an increased risk for lung cancer, as well as for malignant mesothelioma, indicating that this occupational group was (is) exposed to asbestos. Workers exposed to chlorine compounds also seem to run an increased risk for lung cancer. An increased risk for malignant lymphomas among pulp mill workers is a constant finding. The increased risk is observed both among sulfite and sulfate workers, indicating a common exposure. Such an exposure could be wood dust, terpenes, or preservatives present in the wood. An increased risk for leukemias has been found in many studies carried out on pulp and paper workers, but the studies do not permit any conclusions about etiologic factors. In some studies an increased risk for stomach cancer has been found. However, the socioeconomic status of the workers is strongly related to stomach cancer, and factors, such as dietary habits, have not been taken into account in any of the reviewed studies. Hence, no further conclusions can be drawn regarding etiologic agents.