A review of recent literature on school entry medicals (SEMs) assessed whether selective medicals were as effective and/or cheaper than routine medicals. Data were compared with prospective data from the author's 'patch' on a one-year cohort of routine SEMs. Routine medicals showed that 40-50% of school entrants had health problems but selective systems detected fewer. Districts with high morbidity were less able to detect problems early but effective child health surveillance was not related to the number of new problems at SEM. Selection did not reduce costs and could increase costs in deprived areas. The SEM is an opportunity for health education which is valued by parents. On present evidence, selection for medicals at school entry cannot be recommended.