This paper examines the importance of exchange rate risk in the return generating process for a large sample of non-financial firms from 37 countries. We argue that the effect of exchange rate exposure on stock returns should be conditional and show evidence of a significant return premium to firm-level currency exposures when conditioning on the exchange rate change. The return premium is directly related to the size and sign of the subsequent exchange rate change, suggesting fluctuations in exchange rates themselves as a source of time-variation in currency risk premia. For the entire sample the return premium ranges from 1.2 - 3.3% per unit of currency exposure. The premium is larger for firms in emerging markets, while in developed markets it is statistically significant only for local currency depreciations. Overall, the results indicate that exchange rate exposure plays an important role in generating cross-sectional return variation. Moreover, we show that the impact of exchange rate risk on stock returns is predominantly a cash flow effect as opposed to a discount rate effect.