A retrospective survey of the records of 327 patients with multiple injuries was carried out in order to establish the incidence of missed injuries and the reasons for diagnostic failures. Twelve per cent of the patients had an injury not diagnosed at the first examination. The most vulnerable group were motorcyclists in whom the incidence was 23%. Missed injuries tended to be grouped about the major joints. Factors which predisposed to an inadequate initial assessment were poor clinical routine, failure to interpret correctly certain physical signs, poor utilization of X-ray services and, above all, admission of these patients to nonorthopaedic wards.