The primary goal in the treatment of osteoporosis is to prevent skeletal fractures. Modern antiresorptive drugs reduce the number of fractures in patients with moderate osteoporosis, but they cannot repair serious damage to bone structure. Both experimental investigations and clinical trials have shown that daily injections of parathyroid hormone or its amino-terminal fragment (1-34) increase the number and activity of osteoblasts, and accelerate formation of new bone tissue. In postmenopausal women with severe osteoporosis, treatment with the amino-terminal fragment of recombinant human parathyroid hormone, given once a day as a subcutaneous injection, results in a significant increase in the bone mineral density of the spine and proximal femur, without impairing bone quality. 18-month treatment with PTH decreases the risk of both compression fractures of the spine and nonvertebral osteoporotic fractures by more than 50%. Parathyroid hormone in the recommended dose of 20 g daily has proved to be a safe and effective drug, stimulating the reconstruction of structurally damaged bone and significantly decreasing fracture risk in patients with severe osteoporosis.