In an epidemiological study of 286 metalworkers exposed to metalworking fluids (MWF), the prevalence of skin problems was investigated. Minor changes, such as a dry rough skin with slight erythema, were seen in 31%, and major changes, such as more serious and widespread dermatitis, were observed in 27% of all workers. By far the most cases were of irritant origin; in only 2.8% was a contact sensitization established. Exposure to water-based MWF caused irritant contact dermatitis more often than exposure to neat oils. No influence was found of the presence of atopy on the occurrence of dermatitis. Other factors that may result in irritation of the skin are discussed, as well as measures to be taken to minimize insult of the skin.