The purpose of this literature review is to identify the social determinants of child malnutrition in urban slums in Kenya and to review evidence for the impact of interventions that seek to reduce child malnutrition through changing its social determinants. The review will also draw out the implications of these findings for the further development of the NICK (Nutritional improvement for children in urban Chile and Kenya) Project in Kenya. The findings indicate that the main intermediate social determinants of the high levels of child undernutrition (underweight, stunting, and wasting) in the urban slums in Kenya and are poverty, lack of access to enough nutritious food or health services (including antenatal care and birth spacing), low levels of maternal education and poor child care practices. Specific interventions aimed at tackling malnutrition in informal settlements have yet to be systematically documented. These findings suggest that the NICK Project in Kenya should seek to facilitate multisectoral actions to improve access to food, health services and education especially for mothers.