Coconut diethanolamide (CDEA), manufactured from coconut oil, is widely used as a surface-active agent in hand gels, hand-washing liquids, shampoos and dish-washing liquids. CDEA has rarely caused allergic contact dermatitis. During 1985-1992, we investigated 6 patients with occupational allergic contact dermatitis caused by CDEA. 2 became sensitized from a barrier cream, 3 from a hand-washing liquid, and 1 had been exposed both to a hand-washing liquid and to a metalworking fluid containing CDEA. Leave-on products (hand-protection foams) caused sensitization much more rapidly (2-3 months) than rinse-off products (hand-washing liquids; 5-7 years). Due to the extensive use of CDEA and the lack of proper declaration of products, it is difficult to avoid CDEA exposure. No contact allergy to another coconut-oil-derived sensitizer (cocamidopropyl betaine) was found in the patients.