The aim of this study was to explain the relative effectiveness of monetary and fiscal policies in explaining output in Rwanda. The study used a sample of quarterly data for the period 1996-2014. Applying a recursive VAR, the study used 12 variables, including 5 endogenous and 7exogenous variables to the benchmark model and other two specifications were attempted to capture the true contribution of monetary and fiscal policies to variations in nominal output. Obtained results using impulse responses and variance decomposition provide evidence that monetary policy is more effective than fiscal policy in explaining changes in nominal output in Rwanda. In addition, monetary policy explains better output when the VAR model contains domestic exogenous variables than when they are not included, suggesting the relevance of including domestic exogenous variables in VAR specification of monetary and fiscal policies effectiveness on economic variables. Another suggestion is that in order to achieve higher growth, the government of Rwanda should rely more on monetary policy as compared to fiscal policy.