Cyclical intravenous bisphosphonate therapy is widely used to treat children with osteogenesis imperfecta (OI), but little is known about long‐term treatment outcomes. We therefore reviewed 37 children with OI (OI type I, n = 1; OI type III, n = 14; and OI type IV, n = 22) who started intravenous bisphosphonate therapy before 5 years of age (median 2.2 years; range, 0.1 to 4.8 years), and who had a subsequent follow‐up period of at least 10 years (median 14.8 years; range, 10.7 to 18.2 years), during which they had received intravenous bisphosphonate treatment (pamidronate or zoledronic acid) for at least 6 years. During the observation period, the mean lumbar spine areal bone mineral density Z‐score increased from –6.6 (SD 3.1) to –3.0 (SD 1.8), and weight Z‐score increased from –2.3 (SD 1.5) to –1.7 (SD 1.7) (p < 0.001 and p = 0.008). At the time of the last assessment, patients with OI type IV had significantly higher height Z‐scores than a control group of patients matched for age, gender, and OI type who had not received bisphosphonates. Patients had a median of six femur fractures (range, 0 to 18) and five tibia fractures (range, 0 to 17) during the follow‐up period. At baseline, 35% of vertebra were affected by compression fractures, whereas only 6% of vertebra appeared compressed at the last evaluation (p < 0.001), indicating vertebral reshaping during growth. Spinal fusion surgery was performed in 16 patients (43%). Among the 21 patients who did not have spinal fusion surgery, 13 had scoliosis with a curvature ranging from 10 to 56 degrees. In conclusion, long‐term intravenous bisphosphonate therapy was associated with higher Z‐scores for lumbar spine areal bone mineral density and vertebral reshaping, but long‐bone fracture rates were still high and the majority of patients developed scoliosis. © 2015 American Society for Bone and Mineral Research.