A series of 29 patients with primary osteoarthrosis of the hip were studied to evaluate their bone mineral status. A comparison was made with a series of persons with healthy bones. The bone mineral content of the osteoarthrotics, as measured either by gamma ray attenuation in the forearm bones, or as cortical indexes, or obtained from the combined cortical thicknesses of the second metacarpals from the radiographs, was not higher than in the control series. These findings do not support the concept that patients with osteoarthrosis tend to have a higher "mineral density" than healthy people.