This study examined the daily-level association between contact with same-ethnic others and ethnic private regard among 132 Asian adolescents (mean age = 14 years) attending four high schools ranging in ethnic composition diversity. The data suggest a positive daily-level association between contact with same-ethnic others and ethnic private regard for adolescents, who were highly identified with their ethnic group and who attended predominantly White or ethnically heterogeneous schools. In addition, using time lag analyses, contact with same-ethnic others yesterday was positively related to ethnic private regard today, but ethnic private regard yesterday was unrelated to contact with same-ethnic others today, suggesting that adolescents' identity is responsive to their environments. The implications of these findings for the development of ethnic identity are discussed. (Contains 4 figures and 4 tables.)