A series of 252 abortuses, stillbirths and neonates at the University of Ilorin Teaching Hospital and ECWA Hospital, Egbe, in Nigeria, were examined by autopsy dissection between 1983 and 1985. Their clinical cohorts in the nurseries, pediatric wards and those subjected to operations were also reviewed. Primary school children volunteers in two Ilorin schools were also examined in 1987 for cardiopulmonary malformations and umbilical hernia. Incident rates for congenital malformations ranged from 0.08 to 38.27% for congenital groin hernia, 2.39 to 8.73% for umbilical hernia, and 0.21 to 21.05% for the entire gastrointestinal tract. Other incident rates are 0.10 to 7.14% for genitourinary tract, 0.33 to 6.69% for CNS, 0.16 to 5.55% for musculoskeletal system, 0.26 to 4.76% for cardiovascular and 0.06 to 3.9% for bronchopulmonary malformations. The scope of the study is expected to make it adaptable in other developing countries.