The clinical records of 40 patients with X-linked hypophosphatemia who were treated and followed for at least 36 months were examined retrospectively. The patients were divided into those treated with medication only (group A) and those treated with medication and surgery (group B). At follow-up, significant improvement in bowing angles was noted for group B patients compared with those treated medically. There was, however, no improvement in the height of children in group A, and there was a significant decrease in height among the children treated surgically (group B). Neither height nor bowing angles of femurs or tibias at presentation predicted the need for future osteotomies. However, children who eventually needed surgery were found to be obese at presentation significantly more frequently than children who did not require osteotomy.