Occupational hand eczema (OHE) is the most frequently recognized work-related disease in Denmark and the annual cost to society is high. Understanding of the epidemiology of OHE is essential to be able to give appropriate recommendations for its prevention. The study comprised 758 persons, 490 females and 268 males with recognized OHE in the period October 2001 to November 2002. Data were obtained prospectively from the National Board of Industrial Industry Registry and from a self-administered questionnaire (response rate, 82%). The most frequently recognized diagnosis was irritant contact dermatitis (ICD), mainly caused by wet occupations. The proportion of occupational ICD was equal for males and females, 59.7% and 63.1%, respectively. The estimated rates of OHE were high for bakers, hairdressers and dental surgery assistants, and a high proportion of apprentices were found among hairdressers. The prevalence of atopic dermatitis was low (16.4%) compared to previous studies among hand eczema patients. The prevalence of occupational allergic contact dermatitis in the study population was substantially higher among males than females, and the most frequent causes among males were allergy to chromium (leather exposure), rubber additives (gloves) and nickel due to exposure from work tools and metalworking industry.