Both Europe and the United States are confronting the challenges of economic and cultural integration posed by immigration. This article uses the ESS and CID surveys to compare transatlantic public opinion about immigrants and immigration. We find more tolerance for cultural diversity in the United States, but we also find that Americans, like Europeans, tend to overestimate the number of immigrants in their countries and tend to favor lower levels of immigration. The underpinnings of individual attitudes are similar in all countries and immigration attitudes are surprisingly unrelated to country-level differences in GDP, unemployment and the number and composition of the foreign born. An implication of these findings is that acceptance of higher levels of immigration, deemed by many to be an economic need, will require both more selective immigration policies and an emphasis on the cultural assimilation of newcomers.