A series of 177 patients who had posterolateral lumbar-spine bone-grafting has been presented. The clinical result was based on reliefof pain, the need for analgesic medication, the restriction of physical activities, and the return to employment. Sixty per cent achieved good results, and 81 per cent satisfactory results (good and fair). A solid fusion based on roentgenographic evaluation was achieved in 80 per cent. There was high correlation between the clinical result and the presence or absence of a solid fusion in all diagnostic categories except spondylolisthesis. For spondylolisthesis, a one-level posterolateral grafting procedure seemed to be more reliable than a two-level procedure. Compensation considerations and a diagnosed psychoneurosis were factors that were identified as predisposing to a poor clinical result. Postoperative immobilization with a plaster body cast did not improve the fusion rate. Our experience indicates that posterolateral lumbar-spine bone-grafting resulted in a better fusion rate and a greater percentage of good clinical results than those reported for either anterior interbody or strictly posterior bone-grafting techniques.