We investigate the impact of intra-regional migration on wage inequality in the West African Economic and Monetary Union (UEMOA). We exploit unique data from a unified labour force household survey which covers natives and migrants in the seven economic capital cities of that region. We first estimate the counterfactual wage distributions of UEMOA migrants in absence of migration to evaluate the compositional effect of migration (i.e., when wages are treated as exogenous). We find that regional migration increases average wages by 1.8% and generates a decrease in inequality that ranges between −1.5% (for the Gini index) and −4.5% (for the interquartile ratio). This is essentially driven by a reduction in inequality between capital cities, while the effect of migration on within-capital cities inequality is heterogeneous across countries and remains small overall. Second, when accounting for possible general equilibrium effects of migration on stayers’ wages (i.e., when wages are treated as endogenous), we find similar to stronger effects on inequality, albeit with a smaller increase in the average wage.