BACKGROUND Childhood mortality is a serious public health concern. Periodic assessment of its trend is important in evaluating the pattern and planning intervention strategies. OBJECTIVE The study aimed at evaluating the childhood mortality (<18 years) in Delta State University Teaching Hospital, Nigeria. METHODS This is a descriptive retrospective study from 1st January, 2016 to 31st December, 2018 using mortality data from the institution. RESULTS A total of 1,692 children were admitted during the study period, out of which 203 died, giving a mortality rate of 12%. They were composed of 126 males and 77 females with a mean age of 17.5 months. Neonates, children aged between 28 days and 1 year, between 12 months and 5 years and between 5 years and 18 years accounted for 46.8%, 14.3%, 16.3%, and 22.7% of the cases respectively. Sepsis, prematurity, birth asphyxia, congenital anomalies and bilirubin encephalopathy accounted for 30 (31.6%), 22 (23.2%), 15 (15.8%), 13(13.7%) and 5 (5.3%) of the cases respectively. Septicemia (31.0%) and bronchopneumonia (13.9%) were the leading causes of infant death. Leading causes of under-5 mortality (excluding infants) include burns, malaria, anemia/anemic heart failure, traumatic injury, meningitis and pneumonia, accounting for 18.2%, 18.2%, 12.1%, 12.1%, 9.1% and 9.1% of the cases respectively. Among children 5-18 years, meningitis/encephalitis, malignancies, renal disease, road traffic accident (RTA) and burns accounted for 9(19.6%), 8 (17.4%), 4 (8.7%), 4 (8.7%) and 3 (6.5%) cases respectively. CONCLUSIONS We observed excess of male mortality, with neonates being the most vulnerable. These deaths are attributed to preventable causes. There is need to intensify intervention programmes to reverse this trend.