This paper investigates the Feldstein–Horioka coefficients for 13 ECOWAS countries using the recently developed Augmented Mean Group (AMG) estimator over the period of 1975 to 2014. AMG methodology incorporates the issues of endogeneity, heterogeneity and cross-sectional dependence. Furthermore, we also investigate the role of several other macroeconomic factors, Balance trade, inflation, credit and population growth, to improve the international capital mobility. The results show high value of saving retention coefficient (0,76), signifying high association between domestic savings and domestic investment and hence a slow capital mobility or financial integration in ECOWAS countries.