The descriptive epidemiology of sudden death at work was studied in an urban, industrial county. County coroner's records were used to identify the 212 deaths that occurred at work among employed white males in Allegheny County, Pennsylvania in 1979-1982. Occupations and industries with increased risks for either sudden natural deaths or fatal injuries at work were identified by comparison with the white male county employed population. Men employed in service occupations had the highest age-adjusted sudden natural death rate at work (27.0 per 100,000). This was 2.5 times as high as the overall county rate. Men employed in the construction industry had the highest age-adjusted rate of fatal injuries at work (24.3 per 100,000). This was 4.4 times as high as the overall county rate. Twenty-five per cent (17/68) of occupational fatalities involved multiple fatalities or injuries. Only 1 per cent (2/144) of natural deaths at work and 7 per cent (5/68) of fatal injuries had blood alcohol levels exceeding 0.1 mg/100 ml, the level of intoxication. Improvements in the prevention and surveillance of sudden deaths that occur at work are suggested. Coroner's records are suggested for use in future surveillance on sudden deaths at work because they identified more sudden deaths at work than death certificates did.