In this paper, we empirically explore the endogeneity of uncertainty and the interaction between different types of uncertainty and monetary policy using a shock-restricted vector-autoregression model. We find that a contractionary monetary policy shock reduces financial uncertainty, opposite to the findings in the previous literature, while at the same time it also heightens real uncertainty. This discrepancy arises because the model allows endogenous shifts in uncertainty. We also show that endogenous responses of uncertainty amplify the effects of monetary policy on real activity.