A study was undertaken on the mortality of workers exposed to ECH at four European sites with plants producing epichlorohydrin (ECH), epoxy resins, glycerin, and other specialty chemicals derived from ECH. The vital status of 606 individuals with at least one year of exposure to ECH, starting at least 10 years before the final date of the study on 31 December, 1978, were collected. Mortality was analysed for a subgroup with 10 or fewer years of exposure, and another subgroup with more than 10 years of exposure. Four deaths from different cancers were observed against five expected. No excess mortality from cancer was observed in either subgroup or the complete cohort, which could be related to ECH exposure. The small size of the cohort and the limited number of deaths due to low average age (42 years), as well as the short duration of the observation period, do not allow a firm conclusion to be reached regarding the potential carcinogenicity of ECH in man. Current exposure levels are low, but exposure in the early days of production occasionally reached levels high enough to be irritating. We recommend updating the study 5 years from the final date of the present study, i.e. on 31 December, 1983. Within their limitations this and other epidemiological studies so far provide no evidence for an association between occupational exposure to ECH and the occurrence of malignant neoplasms in man.