Glycosaminoglycan polysulfate (GAGPS = Arteparon) is used for the treatment of degenerative joint diseases; it inhibits enzymes that dissociate ground substance, e.g. hyaluronidase, beta-glucuronidase, and acid phosphatase. In turn, an improved synthesis of hyaluronate from the synovial lining cells to hyaluronic acid increases viscosity (Verbruggen and Veys 1977). From January 1975 to December 1979, in the Orthopedic Division of the Clinic "St. Elizabeth" in Saarlouis, West-Germany, we treated 754 patients with a total of approximately 8000 intra-articular injections of Arteparon. The problem with drugs influencing the metabolism of joint cartilage is that the results cannot - for obvious reasons - be as conspicuous as e.g. with corticoid injections, although the latter sometimes involve also marked side-effects. After several courses of therapy, on the other hand, the cartilage-protective effect of Arteparon becomes apparent, with an effect lasting for several months. The indications to include the patients into our study were: arthrosis and other cartilage disorders that had been diagnosed prior to onset of therapy by means of either X-ray, surgery, arthrography etc. Therapeutic results were measured by the parameters: subsidence of pain, recession of edema, improved joint motion, etc. Arteparon, applied intra-articularly, was well tolerated; local irritation, and swelling of the treated joints were reported in only 4.7% of the treated cases; the therapeutic overall result was good. Occasionally, a case of headache was observed, however, no case of joint infection was reported.