256 patients with a clinical diagnosis of contact dermatitis were patch tested with European standard series allergens in a period from 1976 to 1979. Significant positive reactions were observed with all allergens, among which were paraphenylenediamine (7.8%), wood tars (7.8%), formaldehyde (7.0%), balasam of Peru (6.6%), neomycin (5.1%), ethylene‐diamine (0.8%), naphthyl‐mix (0.8%), mercapto‐mix and PPD‐mix (1.2%).North American Standard Series allergens were also patch tested in another 178 patients in the years 1976, 1977, 1979 and 1980. Similar results were obtained with allergens common to both series and, of the others, ammoniated mercury (12.9%), thimerosal (9.5%), captan (5.6%), and hydroxycitronellal and Caine mix (4.5% each) were p