Human knee joint menisci graded according to degenerative alterations were submitted to chemical analysis. Normal menisci contained 72% water, 0.12% DNA, 22% collagen, and 0.8% total glycosaminoglycans with the following glycosaminoglycan distribution pattern: 40% chondroitin 6-sulphate, 10-20% chondroitin 4-sulphate, 20-30% dermatan sulphate, and 15% keratan sulphate. The water content increased with increasing degeneration, whereas the collagen and glycosaminoglycan contents decreased with relative increase of chondroitin 6-sulphate.