Criteria for evaluating the results of treating lumbar spinal disorders vary widely. Comparative analyses of outcome among different therapy protocols are compromised by the diversity among the groups studied, as well as by the varying methods of measuring success. A rating scale is proposed based on the economic and functional status of the patient before and after treatment; anatomic results can be correlated. Application of this method to 34 patients who had undergone posterior lumbar interbody fusion showed a favorable response in 85% with a fusion incidence of 94%. This rating scale is easily applicable and can delineate pre- and postoperative conditions of patients on a semiquantitative basis. A more universal acceptance of common criteria for judging the outcome of lumbar spinal operations will facilitate comparisons among various methods of treatment.