Despite countless initiatives to alleviate malnutrition over the years, it affects hundreds of thousands of children in Sri Lanka. Understanding the determinants of malnutrition, as well as causes of higher childhood malnutrition amongst lower socio-economic groups is important for improving the effectiveness of policies aimed at reducing childhood malnutrition, especially in severely affected populations. This policy brief examines the socio-economic determinants of childhood malnutrition as well as causes of higher childhood malnutrition amongst lower socio-economic groups. The study uses the nationally representative Demographic and Health Survey 2006/07 data compiled by the Department of Census and Statistics.