Our objective was to determine the value of the Ottawa knee rules when applied by users with different levels of clinical training. We used a prospective patient survey by the medical students and surgery residents of a European university trauma centre. The study group consisted of 261 eligible patients who presented with acute knee trauma during a 6-month period. Radiography or follow-up was obtained for each patient. Data were separately analysed according to the degree of qualification of the initial examiner. The Ottawa knee rules had a sensitivity and a negative predictive value of 1.00. Variable degree of medical competence of the users did not alter the accuracy of the rules. Application of the rules would have reduced knee radiography requests by 25%. The Ottawa knee rules remain highly sensitive when applied by medical users with different levels of qualification, such as encountered in a teaching setting.