A community survey of skin disease was carried out in Lambeth, London. A postal questionnaire asking recipients to give details of the presence of skin disease was sent to a stratified sample of 2180 adults; a subsample of 614 persons were interviewed at home and an inspection was made of the exposed parts of their skin. Altogether 92 conditions were identified. These were graded for clinical severity and classified into 13 groups. The overall prevalence of skin disease thought to justify medical care was 22-5%. The most common important condition was eczema with a prevalence of 6-1%. Age, sex, and social class trends in prevalence were found in certain groups of skin disease. Of those with a skin disease thought to justify medical care, only 21% reported having attended their general practitioner in the past six months for a skin complaint. The reported use of medical care and self medication is discussed in relation to the presence of skin disease and other factors.