Direct biomechanical testing of bone undoubtedly provides more information about mechanical integrity then exist several methods, e.g. Ultrasound Transmission Velocity and Bone Mineral Density. These methods are widely used as possible predictors of the bending strength of osteoporotic long bones from ovariectomized rats that may simulate a model for the human osteoporosis. Mechanical properties of rat femurs are detected for the determination the effect of drugs on the quality of rat osteoporotic bone. This project is founded on the cooperation Czech Technical University in Prague, FME, Laboratory of Biomechanics and the First Faculty of Medicine, Charles University in Prague, 3rd Medical Department - Clinical Dep. of Endocrinology and Metabolism. The paper deals methodologies used for the mechanical testing of rat osteoporotic bones in the Laboratory of Biomechanics.