The role of child health clinics in an inner London district was examined by a survey of attenders at 52 baby clinic sessions run by the health authority and a review of the uptake of screening. Differences between social groups were examined using A Classification of Residential Neighbourhoods (ACORN) which is based on census data and requires only the full postcode to classify people. Clinic attendance was frequent among all social groups when a child was aged under six months but then declined, mainly reflecting changing needs. About one-half of the attenders saw the clinic doctor, often following referral by the health visitor, with 15% consulting about physical health problems. Differences occurred between ACORN groups in their frequency and reasons for clinic attendance after six months of age and rates of referral following developmental screening. This suggests that ACORN may be of value in monitoring service use and identifying groups with particular needs for services.