140 of 937 patients (14.9%) with myelomeningocele have vertebral and rib abnormalities. Vertebral deformities were found in 128 cases (13.6%) and rib deformities in 43 cases (4.5%). This is a frequency, which is in comparison with the general population incidence relatively high. Therefore the conclusion is drawn, that roentgenograms showing the entire spine should be done routinely in every case of myelomeningocele. Theories, which try to explain the formation of these osseous deformities, are discussed.