An experiment examined the effects of imagining contact with an illegal immigrant on attitudes towards illegal immigrants and subsequent effects of that attitude change on feelings about other groups (secondary transfer). Compared to a condition in which participants imagined negative contact with an illegal immigrant, participants who imagined positive contact reported more positive attitudes concerning illegal immigrants. Using bootstrapped mediation models, effects of positive imagined contact on attitudes towards illegal immigrants were shown to generalize to other groups that were independently ranked as similar to illegal immigrants, but not to dissimilar groups. This generalization gradient effect was relatively large. Implications for theory and practical applications to prejudice reduction are discussed.