A cohort of 16,124 male pesticide applicators was matched with Social Security Administration and National Death Index (NDI) files through December 31, 1984. In all, 1,082 deaths were ascertained, and death certificates were obtained for 994 (92%). The standardized mortality ratio (SMR) for all causes of death was 98. Although a number of specific causes of death showed SMRs significantly below 100, only one category of cause of death showed a significantly elevated SMR--cancer of the lung, with an SMR of 135. Termite control operators (TCO)--the group with the greatest likelihood of exposure to chlordane and heptachlor--had an SMR for lung cancer of 97, compared with 158 for other pesticide operators. The excess of lung cancer in the non-TCO workers was limited to operators employed as such for less than five years.