European Journal of TraumaAb stract Background and Purpose: Knee injuries are frequently seen in the accident and emergency (A&E) department. A prospective study was carried out to investigate the reliability of the initial diagnosis of knee injuries made in the A&E department. Patients and Methods: All patients (n = 425) who presented at the A&E Department of the Red Cross Hospital in the Hague, the Netherlands, in 1996 with a knee injury were clinically examined and an X-ray was obtained. The patients were reviewed in the outpatient clinic after 4 days and then at 6 weeks. At these times, patients were referred to the orthopedic outpatient clinic for further investigation and treatment as indicated. After 5 years, a final evaluation was undertaken. Results: After 6 weeks, the subsequent diagnosis was found to differ from the initial one in 6% of cases. This finding had no further consequences with regard to prognosis. After 5 years, all patients were approached by telephone. In total, 94% of the patients were contacted and of these, three patients (1%) had been re-referred to the orthopedic outpatient clinic. The final diagnosis of these three patients was different to the initial diagnosis. Of these patients, one needed an arthroscopy, the other two received conservative treatment. Conclusion: The study found that 1% of knee injuries were misdiagnosed at the A&E department. It is therefore beneficial to review patients with knee injuries in the outpatient clinic after 4 days.