This paper develops a simple theoretical model that can be used to account for the determinants of exchange rate pass-through to consumer prices. While recent evidence has found low estimates of pass-through in many countries, there is little consensus on an explanation for this. Our paper argues that sticky prices represent a key determinant of exchange rate pass-through. We make this argument in two stages. First, holding the frequency of price change constant, we show that our model calibrated to data from low inflation countries can reproduce the estimates of very low pass-through for these countries. The principal determinant of low pass-through in this case is the slow adjustment of prices. We then extend the model to allow the frequency of price change to be endogenous. Calibrating to a wider set of countries, including both low-inflation and high-inflation countries, we show that our model implies that exchange rate passthrough is increasing in average inflation, but at a declining rate.