A survey was conducted to determine the incidence of hand dermatoses among residents in Sweden. All residents over 10 years old were asked whether they had skin changes other than common warts on their hands. Those 2499 residents were offered free examinations; 1659 accepted. They were administered questionnaires and their hands and feet were examined. If eczema was found to be present, the entire body was examined. Epicutaneous tests were administered to the subjects having confirmed or suspected cases of contact allergy. Microscopic study was performed in suspected cases of dermatophytosis. All subjects with dermatoses were treated if treatment was considered beneficial. The most commonly observed dermatoses were 827 cases of hand eczema, 141 cases of senile lentigo, and 124 cases of psoriasis. The incidence of the various types of hand eczema were 288 cases of contact dermatitis, 355 cases of traumatic contact dermatitis, 85 cases of atopic dermatitis, 22 cases of nummular eczema, and 99 cases not classified. In the persons given the epicutaneous tests, positive reactions to one or more allergens were seen in 93 percent of those with allergic contact dermatitis, in 25 percent of those with traumatic contact dermatitis, and in 35 percent of those with atopic dermatitis. A total of 246 dermatitis cases were occupationally related. The substances that caused the most frequent positive allergic reactions were several balsams, nickel (7440020), cobalt (7440484), formaldehyde (50000), chromium (7440484), diaminodiphenylmethane (101779), phenolic formaldehyde resins, and cinnamon.