Anorectal anomalies (ARA) are common congenital anomalies. The etiology of ARA is unclear and its pathogenesis is controversial. Cases with ARA often have other non-ARA-associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with ARA were collected in all live births, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population-based registry of congenital malformations. Of the 202 cases with ARA, representing a prevalence of 5.21 per 10,000, 100 (49.5%) had associated anomalies. There were 7 (3.3%) cases with chromosomal abnormalities, and 31 (15.3%) nonchromosomal recognized dysmorphic conditions, including 17 cases with Vertebral defects, Anal atresia, Cardiac septal defects, esophageal atresia or Tracheo-Esophageal fistula, Renal anomalies and radial Limb defects association. Sixty two (30.7%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the urogenital, the musculoskeletal, the cardiovascular, the digestive, and the central nervous systems were the most common other anomalies in the cases with MCA. The anomalies associated with ARA could be classified into a recognizable malformation syndrome or pattern in 38 out of the 100 cases (38%) with associated anomalies. This study included special strengths: each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion, the overall prevalence of associated anomalies, which was close to one in two cases, emphasizes the need for a routine screening for other anomalies in cases with ARA.