Background The first year of life is a critical period of adaptation for a young infant during which the child becomes exposed to a lot of infectious agents and other environmental problems as its immune systems and other organs are developing. Magnitude of deaths within the first year of life is a significant socioeconomic index of any population. Challenges can also be brought to the forefront which can be tackled by appropriate authorities. Objectives To assess the causes of morbidity and mortality amongst infants aged 29 days to 12 months admitted in the emergency Paediatric unit (EPU) of Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto over a 5- year period. Materials and Methods The admission records of children aged 29 days to 12 months were retrieved. Information extracted included socio-demographic data, diagnosis and outcome of admission. These were entered into a study proforma and analysed with SPSS version 23. Results Total admissions were 1776 in the five-year review. Majority were males accounting for 1030 (58%) with M:F ratio of 1.38:1. 972 (55.4%) were aged 6 to 12 months. Top causes of admissions were diarrhoea disease 328 (18.5%), pneumonia 280 (15.8%), sepsis 211 (11.9%), malaria 202 (11.4%) and malnutrition 154 (8.7%). Mortalities were 223 (12.6%). Highest fatalities out of 223 were from sepsis 47 (21.1%), pneumonia 40 (17.9%), malaria 27 (12.1%), malnutrition 25 (11.2%) and diarrhoea disease 20 (9.0%). Higher proportion of the mortalities were in females 14.5% vs 11.2% (X2 = 4.3; p=0.038). Sepsis mortality was high throughout likewise pneumonia but mortality pattern of other disease conditions varied throughout infancy. Conclusion Post-neonatal admissions were mainly due to infections, likewise mortality of which the top causes varied throughout infancy. Females were more proportionately affected by mortality. These insights on the morbidity and mortality patterns calls for more concerted efforts on child survival strategies and targeting this group of infants is imperative.