Risedronate (Actonel 35 mg), which was promoted in Croatia a few months ago, is the latest (III) generation of bisphosphonates, the most efficient anti-resorption drugs that inhibit osteoclast-mediated bone resorption and change the bone metabolism. The effect of risedronate is 10 times stronger than that of alendronate, and 10.000 times stronger than that of etidronate. The bone turnover is reduced while the osteoblast activity and bone mineralisation are preserved. Decreases in biochemical markers of bone turnover were observed as soon as within 1 month and reached a maximum in 3-6 months of Actonel 35 mg application once a week or 5 mg a day. Several major international, randomised and placebo controlled clinical studies (VERT-NA, VERT-MN, HIP...) on more than 15,000 patients over 3-5 years of therapy have confirmed the speed, efficacy and excellent tolerability of risedronate in treating postmenopausal and corticosteroid-induced osteoporosis. After only 6 months of treatment VERT-NA and VERT-MN have shown a significant reduction in vertebral fracture risk versus control group, radiographically by 62% and clinically by 69% in the first year, which remains significant even after 5 years of treatment (50%) of postmenopausal osteoporosis. All the best properties of bisphosphonates have also been confirmed through a significant reduction in the relative risk of femoral neck fracture over 3 years of treatment by 40%, or by as much as 60% in female patients with osteoporosis and prevalent vertebral fracture, compared with controls. With risedronate we can achieve a quick and significant reduction in vertebral fracture risk in postmenopausal women (65%), especially among a high-risk population such as patients on long-term glucocorticoid therapy (70%) in the very first year of treatment. Prevention and treatment of glucocorticoid-induced osteoporosis is recommended in the administration of 27,5 mg of prednisone or prednisone equivalent in a duration longer than 3 months, irrespective of age or gender. Tolerability and safety of risedronate administration in osteoporosis is very good, almost the same as in the control group, although patients with earlier described or ongoing gastrointestinal troubles were also included. The incidence of endoscopically confirmed gastric ulcer in treatment with alendronate is significantly higher (13,2%) versus controls than in treatment with risedronate (4,1%). Risedronate is hence the first line of bisphosphonates for the reduction of vertebral and non-vertebral fracture risks in postmenopausal women with osteoporosis or those with a high risk of osteoporosis. It also efficiently prevents bone loss or improves bone density in men and women on a long-term corticosteroid therapy.