The aim of the present study is to investigate if elbow extension in a supine position may be a diagnostic factor of signiþcant injury, in order to avoid unnecessary radiographs. Material and Method: Seventy patients, from 5 to 80 years of age, who suffered from an acute (< 6 hours) elbow injury, were examined in casualties. The inability to fully extend the elbow actively in a supine position, was deþned as a positive test. In order to avoid bias, the clinical examiner was the same and the radiographs were evaluated by a consultant radiologist, blinded to all clinical examination results. Sensitivity, speciþcity and positive and negative predictive values, along with their 95% conþdence intervals, were calculated for the elbow-extension test. Results: Forty out of seventy patients had a positive test. Elbow fracture or dislocation was identiþed radiographically in twenty-two patients with positive test. Only two out of thirty (with negative test) had a hairline radial-head fracture, which was found in the radiograph. Discussion: Based on the results of this study, the elbow-extension test has a high sensitivity of 92% and a speciþcity of 61%. The above clinical sign is valuable in the prediction of severe elbow injuries. Conclusions:the elbow-extension test can be considered as a sensitive screening test for acute elbow injuries. Patients with negative test may safely be treated without radiographic aid. Children with negative test may avoid useless radiological exposure.