Between 1976-1993, 302 patients were diagnosed to have Hirschsprung's disease (HD) in Hacettepe University Children's Hospital. All patients have been searched for the occurrence of associated anomalies and other parameters including 1) sex, 2) gestational age, 3) birth weight, 4) length of aganglionic segment, 5) familial occurrence, 6) consanguinity. Forty-nine of 302 patients were proved to have 83 associated congenital anomalies together with HD. Distribution of anomalies was as follows; central nervous system and special senses 28.92%, genitourinary system 26.51%, skeletal 24.09%, gastrointestinal 12.05%, cardiovascular 8.43 %. In eleven patients more than one anomaly involving different systems were detected; only one of these patients was female and six of them have shown short segment disease. Down's syndrome was present in 5 patients. Female:male ratio was 1:4.2 for the whole series and 1:6 for the patients with Hirschsprung associated congenital anomalies (HACA). In the HACA group the percentage increased in favor of long-segment and extensive aganglionosis without statistical significance (p > 0.05). The majority of patients were term babies and their birth weights were between 2500 g < 3500 g. Consanguinity was present in 36 families. No affected parents were detected but two sisters and four brothers were proved to have HD. Three pairs of twins, one of which was monozygotic, and all showing discordance were detected. There was no difference between HACA group and HD without HACA in terms of sex, birth weight, length of aganglionic segment and consanguinity. Although HD seemed to be genetically heterogeneous HACA did not have a genetically different origin from that of HD.