This study is composed of two main parts. The aim of the first part was to investigate the effect of heparin, calcitonin and tamoxifen on osteoporosis initiation and progress through biomechanical means and, thus to assist in clinical usage of these drugs. For this controlled experimental part of the study 32 female New Zealand white rabbits were used. Whole-bone femur, humerus and tibia specimens were subjected to 3-point bending tests while sections from the proximal ends of the same specimens were subjected to compression tests. Treating the rabbit bones as thick walled elliptic tubes with constant wall thickness the stifnesses of the bones of the medicated groups were compared with those of the control groups. The results showed that heparin induced osteoporosis as previously claimed by the common evidence, tamoxifen was effective in reducing the effect of heparin and calcitonin did not yield any conclusive result. In the second part of the study, ultrasonic properties of osteoporotic human femur heads were investigated. Ultrasonic velocities and moduli of elasticity in the tangential, the radial and the axial directions were determined experimentally using seven osteoporotic human specimens. Ultrasonic attenuation in terms of Broadband Ultrasonic Attenuation Index in osteoporosis was attemped to be determined in three directions using three different frequencies. The results were compared with the Singh indices of the same specimens and the efficiency of the methods were discussed. The ultrasonic methods used were concluded to be useful but accurate and precise measurements need uniform sampling considering the age and the sex of the patients, the degree of osteoporosity, the direction and the position of the prepared specimens in bone.