Extensive evidence has been found in literature for the role of institutions in determining the outcomes of a number of macroeconomic variables. This evidence is however inconclusive in the case of trade. In this paper, the gravity model of trade is employed in an empirical assessment of the relationship between institutions and intra-sub-regional trade. In this regard, the overall impact of the quality of institutions is examined, as well as the impact of the difference in quality of institutions between trading countries, on bilateral trade within the ECOWAS (Economic Community of West African States) region. The empirical results show evidence of significant impact of differences in the quality of institutions on intra-sub-regional trade.