The bone mineral content was measured by gamma absorptiometry at two levels on the forearms, proximally on the shafts and distally close to the wrist, in 53 cases of primary coxarthrosis. The bone mineral content at the distal measuring site, representing trabecular bone, was increased in coxarthrosis cases as compared with normal controls; the difference was significant only in women. At the proximal measuring site, representing cortical bone, there was no significant difference. The findings support the concept of impairment of the resilience of the juxta-articular trabecular bone as one factor contributing to the pathogenesis of arthrosis.