The purpose of this paper was to analyze empirically the determinants of interest rate in Rwanda. The specific objectives were to analyze the trends of interest rate, Investment, Money supply and National Saving in Rwanda, to find the relationships between, Money supply, Investment, National Saving and Interest rate in Rwanda. The findings showed that there were the upward and downward trends between Interest rate and its Determinants in Rwanda, and Determinants of Interest rate has both short run and long run relationship. Furthermore, interest rate, money supply and national saving have the same trend which was an upward trend and there was a long and short run relationship that exist between interest rate, Money supply and investment but negatively. However, the provided recommendations were to reinforce national saving and money supply in the economy, thus these will have a positive impact on interest rate in Rwanda and the Government of Rwanda should continue to encourage investors to invest in Rwanda and may continue to revive the money supply in order to reduce inflation.