1. An account of experiences in seventy-five cases with a new method of treatment of low back pain and sciatica caused by intervertebral disc lesions has been presented. The method is based on the fact that chymopapain, a proteolytic enzyme, can break down displaced intervertebral disc material without deleterious effects upon adjacent tissues.

2. Chymopapain was injected into intervertebral discs by the postero-lateral or preferably the lateral approach. Two milligrams per disc constitute an effective dose. The enzyme was administered to seventy-five patients who were potential candidates for laminectomy. These patients were followed for four to thirty months and results were graded as "good" (76 per cent), "fair" (15 per cent) and "poor" (9 per cent).

3. Although untoward reactions have been encountered, none of these has been attributable to chymopapain.

4. Our investigations have convinced us that enzymatic dissolution of a lumbar intervertebral disc lesion is a safe, effective method of relieving sciatica and low back pain in selected cases.