The aim of this study is to analyse the impact of agricultural output on economic growth in West Africa using the case of Benin. Time series data covering the period of 1961 to 2014 were used. The data were analysed through a Vector Error Correction Model (VECM). The results reveal that there is a long run, or equilibrium, relationship between agricultural output, industrial output, capital and GDP. The error correction model indicates that 21.6 percent of the discrepancy between long run and short run GDP is corrected within a year. The variance decomposition shows that the largest contribution to shocks in GDP is its feedback shocks. The contribution of agricultural output to shocks in GDP is less than 2% for the first three year period and about 6% for the ten year period. Capital contribution to shocks in GDP is about 3% for the first three years and more than 15% for the ten year period. Hence, apart from feedback and capital shocks, GDP is most influenced by agricultural output. Therefore, capital formation is primordial to economic growth in Benin but the economic activity upon which capital should be primarily invested is agricultural production. Acknowledgement : The accomplishment of this study has been possible because of the financial, technical and moral support of a number of persons and institutions. Thus, I express my unreserved and profound gratitude to ECOWAS and the Association of African Universities (AAU) for according me this M.Sc. scholarship at the University of Ibadan. My special recognition and deepest gratitude also go to my supervisor and Head of Department, Prof. M.A.Y. Rahji for his constructive contribution to this research. Thanks for accepting me as an international student in your department and for your incessant advices.