The occupations most highly associated with an increased incidence of cancers belonged to the chemical subgroup. These occupations are barbers, operatives in the chemical industry, operatives in the leather industry, painters and printers. Occupations related to inhalation of combustion products are bakers, deliverymen and routemen, kitchen workers, locomotive engineers, mechanics and repairmen, stationary engineers and firemen. Elevated relative risks showed up in the chemical subgroup among the barbers (cancer of the larynx), operatives in the chemical industry (cancers of the larynx and stomach), operatives in the leather industry (cancer of the oral cavity and pharynx, larynx and bladder), painters (esophagus and stomach) and the print workers (cancer of the oral cavity and pharynx). Occupations in the combustion subgroup appeared to be less associated with an increased incidence of cancers than those in the chemical subgroup. Moderately elevated relative risks appeared among bakers in malignant lymphomas, bus, taxi and truck drivers in cancer of the pancreas, locomotive engineers in cancer of the buccal cavity and pharynx and lymphomas and mechanics and repairmen in cancers of the nose, pancreas and prostate. Only a few relative risks were statistically significant such as skin cancer (other than melanoma, age group 14-60) and prostate cancer in mechanics and repairmen.