A study of 55 consecutive knee arthroscopies under local anaesthesia was undertaken, in order to evaluate the effectiveness, patient satisfaction and acceptability of the procedure. Knee arthroscopy was performed without a thigh tourniquet under low volume (20 ml) local anaesthesia using half the recommended safe dose of anaesthetic agents, as a single intra-articular injection together with skin infiltration of the arthroscopic portals. The diagnostic accuracy and effectiveness of the procedure was similar to that of surgery under general anaesthesia. Sixty-two lesions were diagnosed and 48 surgical procedures were successfully carried out in 53 patients. All but one of the questioned patients (97 per cent) were satisfied with the procedure which caused little or no discomfort in 94 per cent of cases. It is concluded that knee arthroscopy under local anaesthesia may be considered as a reliable, well tolerated and safe alternative to conventional procedures.