Aim: To evaluate the spectrum of co-morbidities in severe acute malnutrition and study its association with unexpected dyselectrolytemia in diarrhea. Methods: The study was an observational study which was carried in the Department of Pediatric, Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar, India for period of 1 year from April 2019 to March 2020. Total 110 Children below 5 year age with severe acute malnutrition (SAM) were included in this study. Various co morbid conditions in study population were identified. All the laboratory examination was done with standard method. Results: Out of these 110 patients, 70 (63.64%) were males and remaining 40(36.36%) were females. Male to female ratio was 1.75:1. Maximum numbers of patients were in the age group of more than 1-3 year which constituted 45(40.90%) cases. Majority of children with SAM were having co-morbidity in the form of Anaemia (85.45%), Diarrhoea (64.55%) followed by Pneumonia (27.27%), Rickets (24.55%), Tuberculosis (14.55%), Otitis media (10.91%), UTI (9.09%), Celiac (4.45%), Hypothyroidism (2.73%), & HIV (1.82%). In SAM children presenting with diarrhea (n=71), Hyponatremia was present in 49 cases (69%) & Hypernatremia in 2 (2.8%) cases. No statistically significant difference was found with hyponatremia in diarrheal or non-diarrheal cases of SAM (P value of 0.07). Serum Potassium levels of 110 SAM children were analysed. It was found that 21.82% SAM children were having hypokalemia. Hypokalemia was found in 13.64% of diarrheal cases & 8.18% in nondiarrheal cases. Conclusion: Co-morbidities identification and treatment in SAM children is key step in reducing morbidity and mortality associated with SAM.