Present evidence convincingly indicates that workers with occupational skin disease are more frequently affected by atopic skin diathesis than the general working population. Population-based studies estimating the impact of atopic skin diathesis on occupational skin disease in various occupations have not been reported to date. We analyzed data of all initial reports of occupational skin diseases recorded in the register of occupational skin diseases in northern Bavaria, Germany, from 1990 to 1999. The main outcome measure was the attributable risk of atopic skin diathesis on occupational skin disease within 24 occupational groups that are most hazardous to the skin. Of the 5285 registered cases, 3730 had a confirmed occupational causation. Among these, 1366 workers (37%) presented an atopic skin diathesis. Assuming a prevalence of atopic skin diathesis of 20% in the total population, we found that 21.6% (95% confidence interval 19.4; 23.7) of occupational skin disease cases within 24 occupational groups may be ascribed to this endogenous risk factor. The attributable risk of atopic skin diathesis helped to explain a large proportion of occupational skin diseases. Empirical evidence supports the importance of surveying atopic skin diathesis as part of an occupational skin disease prevention strategy.