This is a retrospective observational hospital-based study aimed to determine the prevalence and outcome of severe acute malnutrition in children less than five years admitted to Omdurman Paediatric Hospital during the period January 2014 to December 2014. Data was collected from patient's hospital records during the study period. Ethical approval and permission to access patients' record were obtained. A total of 593 children with severe malnutrition were identified; 305 of cases were male (51.4%) with a male: female ratio of 1:0.9. The mean age these children was 22.3 months. Children 36-59 months were least affected. 35.4% were classified as low socioeconomic class, 22.9% classified as an average class and there were no sufficient data to classify the remaining. The overall prevalence of severe malnutrition was 6.5%, and the general mortality rate was 2.4% while mortality rate among children with severe malnutrition was 9.3%. Among the 593 admitted children with malnutrition, 407 (68.6%) had marasmus, 141 (23.8%) had kwashiorkor and 45 (7.6%) had marasmic-kwashiorkor. The highest prevalence and mortality rate occurred in September. The most common clinical presentations were gastroenteritis, malaria, urinary tract infections, giardiasis, tuberculosis and AIDS. Only 10.8% of the admitted children were exclusively breast fed for the first three months. 33% were fully vaccinated. Overall 75.7% improved and discharged, 15% discharged against medical advice and 9.3% died. We concluded that prevalence and mortality among children with acute severe malnutrition at Omdurman paediatrics hospital were high, and the current management strategies require review to identify the causes. We recommended adopting policies to manage malnutrition in the community and hospitals.