Hunger and poverty are main critical issues in less developed countries (LDCs) and can be attributed to the fact that almost 70% of the LDC populations are employed in the agricultural sector. Although the international trade can reduce food insecurity in LDCs, for example, facilitating the access to larger markets, the volatility in food prices since the late 2000s has negatively aff ected the food availability. Th is study examines the eff ects of trade on the food security and traces a U-shaped relationship between two variables, using 2000-2010 panel data for the LDCs. Th e results are robust across different methods and show that the food security decreases in the initial stages of the trade expansion but increases beyond a given threshold. Th e key fi nding of this study is the U-shaped relationship between trade and food security, which suggests that the policy makers should pay more attention to expanding investments in the agricultural productivity, particularly from the viewpoints of the self-suffi ciency and self-reliance.