We investigate the impact of regional migration on average wages and 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 capitals of the region. We first estimate the counterfactual wage distributions of UEMOA migrants in absence of migration to evaluate the effect of regional migration when the effect of migration is purely compositional (i.e., when wages are treated as exogenous). We find that regional migration increases average wages by 1.8% and entails 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 countries, while the effect of migration on within-country inequality is heterogeneous across countries and remains small overall. Second, when accounting for possible general equilibrium effects of migration on stayers' wages, we find similar to stronger effects on inequality, albeit with a smaller increase in average wages. The later result is due primarily to the fact that we now account for the predominant pattern of migrants' negative to intermediate self-selection, which tends to depress natives' wages at destination while only mildly affecting wages at home. The former result is due to the fact that regional migration in the UEMOA takes place mostly from low-wage to high-wage countries, which in combination with the general equilibrium effects described above, leads to a larger decrease in between-country inequality than in a setting with exogenous wages.