Ensuring food security remains a major challenge confronting West African countries1. Though food production has increased in the recent past, the region as a whole is not likely to meet the first Millennium Development Goal (MDG) of halving the number of malnourished people by 2015. Nigeria is a leading food producer and marketer in the sub-region – it is the largest producer of almost every major agricultural product and has the largest market for agricultural commodities in West Africa. While different studies have recognized the leading role of Nigeria in the region, very few have researched into the role of Nigerian agriculture in West African food security. Given the significance of the Nigerian economy in West Africa – with approximately 60 percent of the population and over 50 percent of regional gross domestic product (GDP) – it is important in the context of regional initiatives to understand the country’s role in regional food security (World Bank, 2006). Understanding Nigeria’s role is also important for strengthening regional cooperation for collective action to achieve improved food security in the region. The main objective of this study is to examine the role of Nigerian agriculture in West African food security. The study discusses the implications of Nigeria’s agricultural production, the potentials for Nigerian export of agricultural products to enhance regional food security, and the role that the Comprehensive Africa Agriculture Development Program (CAADP) could play in supporting agricultural research and development (R&D) efforts in the region. The study is based on a critical review and analysis of secondary information on Nigerian agriculture in relation to cross-border trade and food security in the West Africa region. The data were obtained from the Central Bank of Nigeria (CBN), the Food and Agricultural Organization statistical database (FAOSTAT), and databases of the Economic Community of West African States (ECOWAS) and the National Bureau of Statistics (NBS). The study showed that, on average, 17 percent of the 280 million people living in West Africa are still food insecure, while about 30 percent live below the poverty line. Thirty-three percent of children under five years of age are stunted, 28.3 percent are underweight, and 10 percent are wasted. Average dietary energy supply (DES), a measure of food security, ranges from 2,500 kcal per capita per day in the coastal regions to 2,400 kcal per capita per day in the savanna regions. In terms of contribution to regional food security, however, Nigeria currently contributes only 51 percent of the total food supply in West Africa. Endowed with the largest agricultural potentials in the region, there are opportunities for Nigeria to contribute more to regional food security, when constraints such as low mechanization, inadequate access to improved inputs, poor markets, insufficient access to credit, policy inconsistency, and inadequate infrastructure are removed. It was shown that agriculture and trade are the two main drivers of food security and that, in these two sectors, Nigeria is the leading country with the greatest potentials in West Africa. Therefore, with increased integration, Nigerian agriculture could contribute in no small way to improving food security in the region. In terms of production of cereals, root and tubers, legumes, and livestock products; the reviewed literature shows that Nigeria has the greatest potentials in the region for production and export to other countries. Increasing the capacity of Nigeria through regional cooperation for increased production of these agricultural commodities could further improve food availability in the country, which could enhance food security in the region as a whole. In this regard, the ECOWAS common agricultural policy could focus more on the interface between it and regional food production hubs such as Nigeria in fulfilling its mandate. International donor agencies and development partners could also focus on supporting Nigeria’s efforts at increasing food production and supply. In particular, they can increase their support for Nigeria’s agricultural R&D, in addition to assisting the country to attract foreign direct investment to the agricultural sector to boost 1 West Africa is comprised of the Republic of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone and Togo. It covers a total land area of 5,112,903 Km2 with a total population of 280 million people in 2008 (USAID, 2010). vi food production. In terms of trade, the study showed that the volume of intra-regional trade between Nigeria and ECOWAS countries is small at the moment. Regional organizations such as ECOWAS and the West African Economic and Monetary Union (UEMOA) have been pursuing the goals of regional integration in trade through the establishment of a common external tariff (CET) and other harmonization policies. Strengthening these regional initiatives will improve trade volumes between Nigeria and West African countries, a factor which the study identified as an important ingredient for assuring regional food security.