Abstract
An attempt has been made to evaluate the evidence for the likely benefit or otherwise, of the obligatory three-yearly checks as defined within the terms of service for doctors in general practice introduced to British general practitioners in April 1990. The content, interval, age groups, ethics, organizational cost, yield and outcome of the three-yearly checks are examined. No particular evidence is apparent which should deflect general practice from its present opportunistic approach to screening, and the already established national screening programmes.