Ninth- and 11th-grade students (N = 379) were surveyed regarding their evaluations of excluding someone from a social group solely on the basis of his or her social reference group membership. Individuals evaluated exclusion in ambiguous and nonambiguous situations. Judgments and reasoning about exclusion were compared with judgments and reasoning about a more prototypically moral situation (denial of resources). Overall, participants evaluated exclusion as less wrong than denial of resources and used fewer moral and more conventional reasons to justify their judgments. Participants relied more on their group knowledge or stereotypes in evaluating ambiguous situations and more on their personal knowledge in evaluating nonambiguous situations. Age- and gender-related differences in evaluations, reasoning, and use of stereotypes were also found.