AbstractEighteen primary brain cancer deaths among male workers at one Texas petrochemical plant from 1965–1980 are reported. Federal officials from OSHA and NIOSH are performing with company cooperation an historical prospective cohort mortality study, a case‐control study, and neuropathological case confirmation. Average age at death was 53 (range 30–66). Median employment was 21 years and median latency was 24 years. 15/18 tumors were glioblastoma multiforme, an unusual histologic distribution. A preliminary estimate reveals a plant‐wide excess brain cancer risk twice expected among 6,800 white males at the plant since 1941. Brain cancer mortality rates in surrounding counties are in the median range for US counties from 1950–1969. Ten recognized or suspected carcinogens are present in quantities>106lbs/yr. To date no common chemical exposures or work assignments have been identified among the cases. Data on 26 experimental brain carcinogens and relevant epidemiological studies are