This work is part of a more extensive,still ongoing, research which aims to provide a morphological assessment and interpretation of congenital malformations on ancient bones. The study of frequency and distribution of congenital malformations on juvenile osteological remains may provide interesting insight and critical observations in assessing the role of those factors that are responsible for child's mortality. In the present study we describe and discuss two cases of congenital spinal malformation refer to failure in the separation of vertebral arch elements between contiguous vertebrae. The skeletons belonging to two children who died in early childhood, between 0 and 6 years of age. The research was conducted on 132 juvenile individuals came from nine necropolises located in north an middle Italy, from ancient and late Roman times to late medieval times.