Many studies have examined the impact of the size of the neighborhood minority population on prejudicial attitudes of majority residents. However, few studies have investigated how residents of different ethnic origins evaluate different ethnic outgroups based on the shares of these particular ethnic outgroups in their neighborhood. Based on the belief congruency theory and social identity theory, we propose that the effect of outgroup size on outgroup attitudes depends on the socioeconomic and cultural differences between ethnic groups. Multilevel analyses of Dutch survey data gathered among Turkish, Moroccan, Surinamese, Antillean, and native Dutch residents indicate that for most groups outgroup attitudes are not influenced by the share of the particular outgroup in their neighborhood. For some ethnic groups, however, the size of a particular outgroup is associated with less positive attitudes toward that outgroup. Differences in the effect of outgroup size on outgroup attitudes only partly correspond with cultural differences and socioeconomic status differences.