Aims-To summarise and critically evaluate research conducted in the UK between 1962 and 1996, on the eVectiveness and eYciency of the school entry medical (SEM) examination. Methods-An electronic search of a large number of databases, in conjunction with a search of reference lists, and sources in the grey literature produced a total of 64 studies. Results-Only one overview and 16 primary studies met the review's broad inclusion criteria. The results showed significant diVerences in the identification and referral of new and ongoing problems not only between the routine and selective SEM but also within the two types of SEM examination. There were also large diVerences in the numbers of children selected for SEM examination. No study included in the review defined either the methods or the criteria used to identify children as screen positive. No study provided follow up of children after referral to estimate the positive predictive value or yield of the screening, or follow up of the whole cohort to identify false negative cases. Conclusion-Data on the eVectiveness and eYciency of both the routine and selective SEM examination in accurately identifying children with new or ongoing health problems are not available at the present time. The studies reviewed here demonstrate the fragility of the evidence on which the school entry medical is based, and call into question the ethical basis of this programme. (Arch Dis Child 1998;78:301-311) Keywords: systematic review; selective school entry medical examination; screening Over the past two decades there has been a gradual shift from the routine to the selective school entry medical (SEM) examination. While there is very little evidence available at the present time to indicate the full extent of this change, it would appear that many purchasing authorities have viewed the continuation of the routine SEM as an unnecessary expenditure. This change has meant an end in many parts of the UK to the routine examination of all children at school entry.SEM examinations were established almost a century ago, before concepts such as "eVective health care" and "evidence-based medicine" were developed. Political concern about public health led to the development of a service in which all children were examined by doctors in school in order to document the prevalence of disease and disability. It was an exercise in population health needs assessment carried out with a view to defining and implementing public health interventions. The information about health needs in school children was collated and published in the reports of the medical oYcers of health, and was used to make the case for public health interventions such as free school milk, free school meals, communicable disease control measures, and new services such as school eye clinics. As clinical services were set up to meet the needs of children with health problems, the SEM examination acquired another function-the identification of individual health needs in order to oVer clinical or individual intervention...