Objectives: To determine whether intravenous bisphosphonate treatment is helpful for children with osteoporosis pseudoglioma syndrome who have severe osteoporosis. Methods: Three children (ages 9 to 11 years) with osteoporosis pseudoglioma syndrome who had multiple vertebral collapse were treated over a 2-year period with intermittent intravenous bisphosphonate infusions (pamidronate in 2, clodronate in 1). The responses to therapy were assessed with clinical and radiographic evaluation and bone densitometry of the spine. Results: All 3 subjects reported early reductions in bone pain and improved mobility. Radiographs showed dense new bone in the vertebral end plates and remodeling of the vertebral bodies. Areal bone mineral density at the lumbar spine (age-appropriate SD score) improved from a mean of –4.5 before treatment to –2.8 after 2 years (P <.05). No new fractures occurred, and side effects were minimal. Growth and pubertal development proceeded normally. Conclusions: Intravenous bisphosphonate therapy appears safe and beneficial in patients with this condition and may prevent progressive vertebral deformity. (J Pediatr 2000;137:410-5)