We investigate the output effects of banking and currency crises in emerging markets, focusing on whether "twin crises" entail especially large losses. Recent literature emphasizes the costs of financial crises, and suggests that twin crises are particularly damaging to the real economy. Using a panel data set for 1975-97, we find that currency (banking) crises are very costly, reducing output by about 5%-8% (8%-10%) over a 2-4 year period. The cumulative loss of both types of crises is therefore very large. We do not find, however, additional feedbacks or interactive effects associated with twin crises further damaging the economy.JEL codes: F43, G15, G21, O40 Keywords: banking crisis, balance of payments, twin crisis, growth.Severe financial crises occur with some frequency in emerging market economies-more than 51 currency and 33 banking crises episodes over the past 25 years in our emerging markets sample and 20 occurrences of "twin crises"-currency and banking crises that occurred simultaneously. Moreover, this frequency of financial crises appears to be a reoccurring phenomenon, persistent over time and across regions of the world (Bordo et al., 2001, Glick andHutchison, 2001). A large and growing empirical literature attempts to explain the factors that cause currency, banking, and twin crises, as well as their timing, on the basis of macroeconomic, institutional, and structural factors (see, for example, Arteta and Eichengreen, 2002, We thank participants at the UCSC workshop series on currency crises for helpful suggestions on an