Malnutrition is one of the most common causes of morbidity and mortality among adolescents and is now considered to be one of the largest risk factors responsible for the global burden of disease, along with poor diet. This review assesses the impact of preventive nutrition interventions (including nutrition education and counselling; micronutrient supplementation/fortification and macronutrient supplementation) to improve the health and nutritional status of adolescents aged 10-19 years in low- and middle-income countries (LMICs). This Campbell systematic review summarises findings from 10 studies on preventive nutrition interventions among adolescents in LMICs.