Several studies have found increased risks of cancer among workers in the meat industry, particularly lung and hematologic cancers. Relevant publications were obtained through a computerized literature search with the key words "cancer", "lung cancer", "hematologic neoplasms", "meat products", "abattoirs", and "slaughterhouses", and the evidence available from analyses of routine data, proportionate mortality and incidence studies, and cohort and case-control studies was reviewed. These analyses suggest a significant excess lung cancer risk among meat workers. This risk was associated the most strongly with exposure to animal slaughtering or freshly slaughtered meat or to biological material contained in blood and animal fecal matter, and it was greater than could be attributed to smoking. This finding suggests an etiologic role for biological exposure; however, the specific exposure(s) responsible are unknown, and further research is clearly required. The results of studies of hematologic cancers have been less consistent, but they suggest a small excess risk for leukemia in association with similar exposures.