Thirty-seven (20 per cent) of 186 children who had myelomeningocele whose records were reviewed had sustained a total of seventy-six fractures. The frequency with which the fractures occurred was related directly to the level of neurological involvement. Thirteen (41 per cent) of the patients who had involvement at the thoracic level, fifteen (36 per cent) who had involvement at the upper lumbar level, eight (10 per cent) who had involvement at the lower lumbar level, and one (3 per cent) who had involvement at the sacral level sustained fractures. Sixty-five (86 per cent) of the fractures occurred before the child was nine years old, fifty-eight (76 per cent) were judged to be secondary to the limb being in a cast, and seventy-four (97 per cent) involved the lower extremity. Eleven patients, all of whom had thoracic or upper lumbar involvement, sustained fractures of multiple extremities. All fractures of the lower extremity were distal to the level of neurological involvement; they occurred predominantly in the femur in patients who had thoracic involvement and in the tibia in patients who had lumbar involvement. All of the metaphyseal and diaphyseal fractures healed satisfactorily, whether they were treated by immobilization in a plaster cast or in a bulky Webril dressing, although there were fewer complications in the latter group. The seven fractures that involved the physeal plate were a major problem, as three (43 per cent) had delayed union and two (29 per cent) developed premature growth arrest.