The occurrence and course of hand dermatitis in hospital workers was studied on the basis of the patient register of an occupational specialist and by a clinical follow-up study. About 1% of all the hospital workers had had dermatitis, cleaners, kitchen workers and nurses most frequently. 54% of the patients who were clinically studied had suffered from periodic symptoms and 35% had current hand dermatitis. Those who had previous or present atopic dermatitis had most frequently developed dermatitis during the first year of their service. An atopic constitution seemed to predispose to the development of permanent or periodic hand dermatitis. The patients with sensitivity to nickel or fragrances had relapses in the majority of cases. During the study period, the incidence of new dermatitis cases was constant, but the number of days sick leave showed a decreasing tendency.