One hundred twenty probands with primary osteoarthrosis of the hip or knee were examined prospectively; there were 194 controls. In addition, 193 patients with hip or knee arthrosis were examined retrospectively. Restriction of rotation on physical examination accurately differentiated arthrotic hips from normal ones. Among women, 38% of the controls and 49% of the probands had Heberden nodes (P more than .1). Their prevalence increased with age. Individuals with multiple arthrosis joints were not older than those with single joint involvement, and they has a similar prevalence of nodes. Of the probands, 14% had arthrosis of both the knee and hip. Of those with bilateral hip arthrosis, 33% had knee arthrosis as well. Heberden nodes are unrelated to osteoarthrosis of the knee or hip. Knee and hip arthroses frequently occur together and remain confined to the initially affected joints. They may have a common cause.