Failure to thrive (FTT) refers to inadequate growth in infants and young children, often due to insufficient caloric intake. Causes may be medical, nutritional, or psychosocial, with malnutrition being the most common. Early identification is crucial to prevent long-term impacts on physical growth and cognitive development. Assessment includes a detailed history, physical exam, growth chart analysis, and targeted investigations. Management focuses on nutritional rehabilitation, behavioral interventions, and caregiver support, often requiring a multidisciplinary approach. Regular monitoring and early referral are essential for children at risk of serious illness, psychosocial harm, or those unresponsive to outpatient care. Prevention includes routine health surveillance.