Asian immigrant adolescents have a difficult time adapting to unfamiliar customs and cultural values as well as interacting with other ethnic groups. During intergroup contacts and acculturation, Asian immigrant adolescents have negative experiences such as discrimination experiences, intergroup anxiety, interracial tension, and limited social support. In spite of such stressful and negative life experiences, some research has shown that individuals may develop the ability to thrive or grow from stressful life events. Using grounded theory, we explored the characteristics of positive psychological changes that occurred as the result of stressful intergroup contacts and acculturation from the perspective of Korean immigrant adolescents. We captured three main themes related to stress-related growth: (a) psychological thriving, (b) cultural and ethnic understandings, and (c) culturally attuned relationships. This finding implies that stressful intergroup contacts and acculturation provide an opportunity in which Korean immigrant adolescents develop coping abilities and enhance a sense of personal growth.