Acute malnutrition is a nutritional deficiency resulting from either inadequate energy or protein intake. Children with primary acute malnutrition are common in developing countries as a result of inadequate food supply caused by social, economic, and environmental factors. Secondary acute malnutrition is usually due to an underlying disease causing abnormal nutrient loss, increased energy expenditure, or decreased food intake. Acute malnutrition leads to biochemical changes based on metabolic, hormonal, and glucoregulatory mechanisms. Most children with primary acute malnutrition can be managed at home with nutrition-specific interventions (i.e., counseling of parents, ensuring household food security, etc.). In case of severe acute malnutrition and complications, inpatient treatment is recommended. Secondary acute malnutrition should be managed by treating the underlying cause.