The purpose of this practice-based observational study was to examine the effects of long-term treatment with risedronate in patients with an increased fracture risk. Seventy patients (4 men and 66 postmenopausal women; mean age, 68.0 years) with osteoporosis or osteopenia and clinical risk factors for fractures were treated with risedronate at either 2.5 mg/d or 17.5 mg/week for 5 years. The bone mineral density (BMD) of the lumbar spine and proximal femur, and the structural geometric parameters of the proximal femur were evaluated by dual-energy X-ray absorptiometry with advanced hip assessment software at baseline and after each year of treatment. The lumbar spine BMD rapidly increased during the first year of the treatment and steadily increased throughout the 5-year treatment period. The BMD of the femoral neck and total hip also significantly increased during the first 3 and 2 years of treatment, respectively, then gradually declined and reached the baseline level after 5 years of treatment. The cross-sectional moment of inertia, cross-sectional area, and mean width of the femoral neck region of interest significantly increased during the first 2 years, and these increases were maintained throughout the 5-year treatment period. The femur strength index and section modulus also significantly increased following time courses similar to those of the above three parameters. These results suggest that risedronate produced both a sustained increase in the lumbar spine BMD and improvement in the femoral structural geometric parameters for 5 years of treatment.