A review of seventy-one children with sacral anomalies is presented. The aetiology is discussed and a classification of sacral anomalies is suggested, with three groups of patients: agenetic, dysgenetic and dysraphic. The clinical presentation of each group is discussed and the high incidence of congenital visceral and skeletal abnormalities is indicated in the dysgenetic group. The need for constant urological assessment is emphasised, particularly in the agenetic and dysraphic children.