Aim: To evaluate the spectrum of co-morbidities in severe acute malnutrition with unexpected dyselectrolytemia in diarrhea. Methods: The study was an observational study which was carried in the Department of Pediatrics, Darbhanga Medical College & Hospital, Laheriasarai, and Bihar, India for 18 months. Total 90 Children below 6 year age were include in this study. Various co morbid conditions in study population were identified. All the laboratory examination were done with standard method. Results: Out of these 90 patients, 59 (65.56%) were males and remaining 31(34.44%) were females. Maximum numbers of patients were in the age group of more than 1-3 year which constituted 37(41.11%) cases. Majority of children with SAM were having co-morbidity in the form of Anaemia (85.56%), Diarrhoea (63.33%) followed by pneumonia (26.67%), Rickets (25.56%), Tuberculosis (13.33%), Otitis media (12.22%), UTI (11.11%), Celiac (5.56%), Hypothyroidism (2.22%), & HIV (1.11%). 57(63.33%) SAM children presented with diarrhea of which Hyponatremia in 38 cases (69.09%) & Hypernatremia in 1 cases No statistically significant difference was found with hyponatremia in diarrheal or non-diarrheal cases of SAM. It was found that 20% SAM children were having hypokalemia. Hypokalemia was found in 21.05% of diarrheal cases & 6.67% in non- diarrheal cases. Conclusion: Anaemia, Diarrhea, Vomiting, Respiratory tract infections and vitamin A deficiency are the most common co morbid conditions in admitted severe acute malnourished children in this region. Co-morbidities identification and treatment in SAM children is key step in reducing morbidity and mortality associated with SAM.