During a period of three months, the primary diagnoses made by the duty officer in the casualty department on x-rays taken on patients with orthopaedic conditions were compared with the definitive diagnoses made after a conference with the radiological department. The consequences of possible erroneous diagnoses were also recorded. A total of 634 regions were examined in 555 patients. Incorrect diagnoses were made in 55 regions (8.5%). In 21 of these, alterations in the primary treatment were required. All of the treatments could be corrected by telephone (7) or an additional visit by the patient (14). X-rays of the cranium and the spine are known to be difficult to evaluate by inexperienced doctors. This was also found to be the case in the present investigation.