Several medications have been proven to decrease the risk of postmenopausal osteoporotic fractures of the spine, hip, or peripheral skeleton. However, the optimal duration of treatment with these medications has not been determined. The efficacy data come chiefly from controlled trials conducted over 3 to 5 years in elderly women at high risk for fractures. Some of these trials were followed by open-label extension phases that showed sustained bone mineral density gains over 7 to 10 years. The data pointing to a sustained decrease in the fracture rate beyond 4-5 years of treatment vary across studies and drugs but are generally scant and open to criticism. The published evidence does not suggest a need for stopping osteoporosis medications after the first 4-5 years out of concern about bisphosphonate-induced osteonecrosis of the jaw or alendronate-induced atypical fractures. Given that pharmacotherapy targets patients with severe osteoporosis, continued treatment beyond the first 5 years is probably warranted in most cases.