Osteoporosis and cardiovascular disease are major health problems that lead to morbidity and mortality. Bisphosphonates are among the drugs used most frequently worldwide to treat osteoporosis, especially in older women. B-mode ultrasonography has recently become a valuable tool for early diagnosis of atherosclerotic disease because of its ability to measure carotid artery intima media thickness (CIMT). The purpose of the present study was to investigate whether alendronate sodium therapy has an effect on CIMT in postmenopausal women with osteoporosis. A total of 71 postmenopausal women with osteoporosis were evaluated before and after they began taking alendronate sodium; follow-up was provided for an average of 13±2 mo. Osteoporosis was diagnosed with the use of dual-energy x-ray absorptiometry, and therapy with alendronate sodium was begun at a dose of 70 mg/wk. For CIMT, B-mode ultrasonography was performed on the right and left middle and distal main carotid arteries. Before alendronate sodium therapy was initiated, the average CIMT value was 0.734±0.121 mm; after therapy, the average CIMT was 0.712±0.111 mm. This difference was not confirmed to be statistically significant. Treatment of osteoporosis does not seem to have an effect on CIMT, which is an early marker of atherosclerosis.