This study aims to answer the question of whether investments have an effect on the economic diversification of the countries of the Economic and Monetary Community of Central Africa (CEMAC). The panel data used cover the period 1995-2019 and are extracted from the UNCTAD, WGI and WDI databases of the World Bank. To address the research question, we used panel data econometrics. The results obtained show that private investment improves economic diversification, while public investment hinders economic diversification in the CEMAC. These results imply 1) the need to enhance the attractiveness of private investment in all sectors of the economy and 2) the importance of improving state governance through a shift from the rentier to the developmental state.