Osuoha, Rophina ChionyekaUdenwa, Theresa ANwala, M. Nneka2023-12-102023-12-102021-03-18Erenburg, S. J. (1993). The relationship between public and private investment: The Jerome Levy Economics Institute of Bard College and Eastern Michigan University, Working Paper: No. 85 Erden, L. & Holcombe, R. G. (2005). The effects of public investment on private investment in developing economies, Public Finance Review 33 (5) 575-602 Erden, L. & Holcombe, R. G. (2006). The linkage between public and private investment: A cointegration analysis of a panel of developing countries, Eastern Economic Journal 32 (3)479-492 Ezike, J. E. & Mojekwu, J. N. (2011). The impact of external debt on macro-economic performance, International Journal of Business and Management Tomorrow. 1 (2). Ezeabasili, V. N., Isu, H.O., & Mojekwu, J. N. (2011). Nigeria's external debt and economic growth: An error correction approach, International Journal of Business and Management 6(5), 156-170.https://keffi.nsuk.edu.ng/handle/20.500.14448/970This study empirically analyzed the effect of Public Debt and Private-Sector Investment in Nigeria (1986-2017). This study employed secondary data in the analysis. The study used the ordinary least square method (OLS) and Error Correction Model (ECM) tools of analysis in the investigation of the impact and relationship among the economic variables. The Ordinary Least Squares (OLS) and the Error Correction Models show that there is a strong relationship between Private Investment (PIVN)in Nigeria and Public Debt in Nigeria. Public Debt in Nigeria has a negative effect on the economy both in the short run and long rim especially the Public Domestic Debt in Nigeria and Public External Debts in Nigeria. This is because the more government borrows from both the domestic and the external the more it crowds out investment especially the domestic debt crowds out private investment through lack of access to funds. The ECM result revealed that Public Debt Service in Nigeria has a positive effect on Private Investment (PIVN)in Nigeria, this is because when the government pays back loans or debts, it increases access to funds by the private investors thereby increasing the level of private investment in the country. Therefore, the study recommends that government should design a mechanism for effective and efficient Public Debt Service Management in Nigeria to increase access to funds by private investors and thereby increasing and enhancing Private Investment (PIVN) in Nigeria.enPublic Debt, Investment, Private Sector, External Debt, Domestic DebtArticle