Topographical variations in the composition of cartilage have been described in post-mortem femoral head cartilage. Weight bearing cartilage of the superior region was considerably thicker and had a higher glycosaminoglycan content and lower water and collagen content than cartilage at the periphery and below the fovea. These topographical variations in composition may result both from variations in thickness of the cartilage and from regional areas of degeneration. The composition of cartilage at different depths and with different surface characteristics from different areas of the femoral head was measured. Fibrillated cartilage both from the inferior and superior perifoveal areas had a reduced glycosaminoglycan content and higher water content than intact post-mortem specimens. Cartilage adjacent to fibrillated areas from the superior region did not differ in composition from intact areas of cartilage from the zenith of the femoral head.