Abstract:  This paper examines the crowding out or crowding in effect of foreign direct investment inflow on domestic investment in Africa. Data for the period 1970–2008 were extracted from the UN statistical online database and the World Development Indicator 2009 online database and the study employed a recent panel cointegration estimation technique. The study revealed that foreign direct investment inflow crowds out domestic investment in the ECOWAS region. The study therefore recommends that policy makers in the ECOWAS countries focus on promotional resources to attract some types of foreign direct investment and regulate others. Policies should also be directed at putting in place a better targeted approach to screen foreign direct investment applications to ascertain their productive base before allowing them.