A quantitative study of the vascularity and a qualitative study of the remodelling of the calcified cartilage and subchondral bone end-plate of adult human femoral and humeral heads were performed with respect to age. In the femoral head the number of vessels per unit area was found to fall 20% from adolescence until the seventh decade and in the humeral head 15% until the sixth decade. Thereafter an increase was noted in the femur but none in the humerus. More vessels were present at all ages in the more loaded areas of the articular surfaces: 25% more for the femur and 15% more for the humerus. The degree of active remodelling by endochondral ossification declined 50% from adolescence until the seventh decade in the femoral head, and 30% until the sixth decade in the humeral head, rising thereafter to levels comparable to those found at young ages. More remodeling was noted in the more loaded areas at all ages.