This paper employs a small open economy DSGE model, estimated over 1986-2009, to decompose the dynamic influence of domestic and international prices on the Canada-US real exchange rate. While the real exchange rate mimics the dynamic behavior of the relative price of non-tradables in terms of tradables in response to a non-tradable sector-specific disturbance, the purely tradable component dominates in the case of other shocks, irrespective of their structural origin. Variance decompositions reveal that the sources of the movements in the tradable component lie in unsystematic deviations from uncovered interest parity as well as import price mark-up shocks. Consequently, these disturbances are far more potent than internal tradable or non-tradable sector-specific disturbances in driving real exchange rate fluctuations.