This paper studies the relationship between the size of the fiscal multiplier and the degree of capital mobility in some Latin American countries.Mundell's (1963) andFleming's (1962) models show that this effect could be very large or small (close to zero) depending on the exchange rate and the degree of capital mobility, and the potency of a fiscal policy is inversely correlated with the degree of capital mobility.Based on Mora's (2013) model, we argue that the multiplier might not be negatively correlated with capital mobility in these countries.In other words, the potency of fiscal policy could be small because the degree of capital mobility in Latin American countries is quite low.The empirical findings support our hypothesis.We have found that the size of the fiscal multiplier tends to increase or (at least) to remain around 1.40 in these countries in the short run; however, in the long run, this effect tends to decrease significantly to 0.34.These results also suggest that the effectiveness of fiscal policies in Latin American countries are still large but could be larger if they become more financially integrated with the rest of the world.