The results of a study conducted on 40 osteoporotic subjects of both sexes aged 40-80 are reported with a comparison of the diagnosis of the nature and degree of the osteoporosis obtained by traditional radiography and xerography and, on the same subjects, by computerised bone mineralometry. The latter technique provided accurate and fairly early diagnosis in all subjects considered and it is therefore indicated as an elective method for the diagnosis of suspected osteoporosis. Xerography proved the most reliable of the traditional techniques. It should also be noted that in terms of protection against radiation, BMC is distinctly preferable to other radiological examination techniques since total radiation dose is very small.