In this study, I argue that attitudes toward immigrants in the U.S. are particularly different in metropolitan areas characterized by ethno-racial diversity brought about by immigration in order to explain tolerance toward immigrants as a dimension of cosmopolitanism. I further examine whether the influences of individual and contextual characteristics on attitudes toward immigrants in Houston, the metropolitan research setting, reveal how its inhabitants have gradually been accepting their complex foreign diversity as normal. Using data from the Houston Area Survey, I found that the proportion of immigrants in communities is directly associated with tolerance, that white-collar workers are not more tolerant than non-white-collar workers, and that the effect of education on tolerance toward immigrants is not always positive. The conceptualization of tolerance toward immigrants as a dimension of cosmopolitanism serves to explain tolerance not only as a reflection of public opinion, but as a disposition toward the acceptance of diversity in receiving societies.