A survey of the frequency of associated malformations occurring with anorectal anomalies reviewing a large number of cases has been carried out. The urogenital tract, the extremities and the skeleton are most commonly involved. Esophageal atresia and hypospadias are the most important associated malformations. It was impossible to classify the associated malformations according to the sex of the patient or the level of the anorectal atresia.