A review of the literature makes it evident that occupational dermatoses in construction and building workers probably are the most important dermatological cause of sickness and absence of work in industry. Information on the real medical and social importance of these diseases is scarce. On the one hand published data point out that many working days are lost with important financial consequences. On the other hand it has also been noted that workers, despite more or less extensive dermatological problems, sometimes try to continue their work without even consulting a physician. The available information is based on out-patient records and/or insurance files only. Further investigations by trained dermatologists and experienced industrial physicians are necessary to detect and study early cases of occupational dermatosis. Follow-up studies on the further course are also imperative. Systemic longitudinal investigations will provide a more complete picture of the real medical and social importance of occupational dermatoses in this important branch of industry.