Investment is defining as asset or item that is purchased with the hope that it will generate income or appreciate in the future. In an economic sense, an investment is the purchase of goods that are not consumed today but are used in the future to create with. In finance an investment is a monetary asset purchased with the idea that the asset will provide income in the future or appreciate and be sold at a higher price. The purpose of this paper is to investigate the impact of investment (public and private) on economic growth in Sudan during the period 1999 to 2011. Date were collected from central bureau of statistics. Using these data ordinary least squares method was applied to the linear form of the model. The obtained results showed that: investment has positive impact on economic growth measured by nominal gross domestic product, real gross domestic product and growth rate of gross domestic product. This is similar to what mentioned in economic theory.