Seven children with meningomyelocele and sacral level paralysis were selected for careful study of their early motor development. The Bayley Scales of Infant Development (BSID) and the Movement Assessment of Infants (MAI) were administered at regular intervals from 2 to 18 months of age. While the mean BSID Mental Scale score tended to remain consistent and above —1 SD, the mean Motor Scale score showed a steady decline with age. Mean performance was —1 SD by 6 months and −2.5 SD by 18 months of age. MAI scores reflected hypotonia and delayed development of automatic reactions. Correlations between BSID Motor Scale scores and MAI automatic reaction scores ranged fromr= —40 tor= —77 between 6 and 12 months of age. Comparison of BSID scores of study children with other children of similar age and lesion level suggested that performance of this small sample was typical of infants with meningomyelocele and sacral level motor function.