This study is on “the impact of fiscal policy on investment expenditure in Nigeria. It covers the period of 1970 to 2010. A multiple regression model is specified in the study to assess the impact of fiscal policy on investment, using government expenditure, gross domestic product and corporate income tax. The estimation technique employed in this paper is the ordinary least squares (OLS) method. The study reveals that fiscal policy has a significant impact on investment expenditure in Nigeria. Government expenditure and gross domestic product have significant impact on investment, but corporate income tax has a positive, instead of a negative, impact on investment expenditure in Nigeria. Based on the findings, it is therefore recommended that the government should use an expansionary fiscal policy to encourage increase in investment in Nigeria and government spending should be channelled to capital projects and social overhead capital that will encourage investment, such as constant electricity supply and good road networks.