Little is known about the long-term effects of a course of pamidronate treatment on bone mineral density (BMD) of children with spastic quadriplegic cerebral palsy (SQCP). Nine patients with SQCP who had low bone density and/or history of previous fracture(s) were studied during treatment and more than 1 yr after cyclic pamidronate treatment ended. Over the 12 mo of treatment, spine BMD increases raised average Z-score from -4.0 to -2.8. In the distal femoral metaphysis, BMD increase raised average Z-score from -3.6 to -1.7. Observations posttreatment ranged from 12 to 49 mo. Changes in BMD were variable among individuals. Group spine Z-score an average of 34 mo posttreatment approached pretreatment value. Six of eight patients had final distal femur posttreatment Z-scores the same or better than pretreatment baseline an average of 27.1 mo later. While most but not all gains in BMD were lost over the first 2 yr after treatment, no patient sustained fracture during or after treatment for a cumulative follow-up of more than 27 patient-yr.