Malnutrition is a global health challenge essentially because of its role as a preventable cause of several morbidities and mortality around the globe, especially in children under 5 years. Associated comorbidities and types of morbidity common in children admitted with severe acute malnutrition in Magumeri General Hospital were investigated. This was a retrospective quantitative hospital-based study. Hospital records, ward admission and discharge registers, and patient cards were reviewed focusing on demographic, clinical, and mortality data extracted on all children under 5 years admitted to the Hospital. Data during the period of December 2018 to March 2020 was collected and analyzed using Microsoft Excel 2013 and SPSS version 17.0. 367 children under 5 years with complicated SAM were identified from the reviewed total hospital admissions of 537. 217 cases were male (59.1%) while 150 were female (40.9%). Marasmus was the most common type of severe acute malnutrition (75.2%) while diarrhea, respiratory tract infection, and malaria were the top three comorbidities, majority of the cases were managed successfully with 79.6 % reported to have fully recovered and were discharged, while 17 (4.1%) died. Magumeri is a locality disproportional affected by various insecurities due to the Boko Haram insurgency, resulting in the high prevalence of severe acute malnutrition among children under 5 years, representing 68.3% of total hospital admissions in the same age group, while 81.2 % had at least more than one comorbidity with a significant association between prolonged hospital stay and treatment (p < 0.001). Keywords: Admission, Magumeri, Morbidity, Severe acute malnutrition, and Under 5 children.