Research has consistently shown that discrimination based on ethnic group membership affects the psychological well‐being of ethnic minorities. Recent studies revealed that discrimination is also a relevant experience for international transracial adoptees, who have experienced a unique migration process. Yet, there is still a paucity of studies focused on similarities and differences between how immigrants and international transracial adoptees perceive discrimination and on how perceived discrimination impacts psychological well‐being, also depending on ethnic identity. Our study aimed to fill these gaps by investigating the moderating role of ethnic identity affirmation in the association between perceived discrimination and psychological well‐being, measured in terms of self‐esteem. A comparison between international transracial adoptees and immigrants was carried out in the Italian context. Participants were 119 international transracial adoptees and 90 immigrants, aged between 15 and 24, all categorizing themselves as Latinos. Findings revealed that immigrants perceived more discrimination and showed higher levels of ethnic identity affirmation than did adoptees, but no difference emerged with respect to self‐esteem. Ethnic identity affirmation buffered the detrimental effects of perceived discrimination on self‐esteem among international transracial adoptees but not among immigrants. Results are discussed in relation to practical implications for preventive interventions.