Distribution of skin lesions was studied in 1,012 patients under 10 years of age, with atopic dermatitis. Of these, 812 (80.2%) had an atopic history; 200 did not. Both categories were divided by age into five subgroups (3-5 months, 6-11 months, 1 year, 2-4 years and 5-9 years) and the incidence of lesions in each of 52 skin regions was compared between the positive and negative history groups and between different age groups. The results were as follows. 1. There was a change in predilection site, from the head (the scalp, face and peri-auricular area) to the neck and flexures (cubital and popliteal fossae) between 1 and 2 years of age. 2. The trunk (shoulders, chest, abdomen and back) was the most common predilection site in both infants and children. 3. Only the upper arm was affected more frequently on the external side than the internal side in all age groups. 4. The nose, mamillae, palms and feet were the least affected areas in all age groups. 5. Incidences in the positive history group were no higher than in the negative group.