This study examines cultural differneces in psychosocial maturity experiences between collectivistic and individualistic cultures. Personal, relational, and social dimensions were assessed to explore psychosocial maturity experience of elderly Korean residents in Korea and Canada who were psychosocially well developed through in-depth interviews and a content analysis. According to the results, there were diverse similarities and differences in the psychosocial maturity of elderly Korean residents between the two cultures. First, psychosocially mature elderly residents in both cultures showed positive self-concept and self-satisfaction. However, there were differences in their meaning. Second, in terms of interpersonal relations, the most important and satisfying relationship was the spousal relationship for both cultures, and relationships with children were satisfying. However, there were differences in the meaning of relationships between the two cultures as well as gender differences. Third, psychosocially mature elderly residents in both cultures reported psychosocial factors such as mature aging as a social dimension. Elderly residents in Korea regarded mature aging as a relationship oriented phenomenon, whereas those in Canada reported social attitudes toward mature aging. In addition, elderly residents in both cultures reported greed and harm to others as immature aging. Elderly residents in Korea regarded relational discord as immature aging, whereas those in Canada regarded it as demanding adult treatment from future generation. In terms of transcendence, adjustment was reported as living by going with the flow. Elderly residents in Korea reported adjustment based on fatalism, whereas those in Canada showed some religious meaning. Finally, psychosocially mature elderly residents showed a positive view, acceptance and life integration. These results are discussed from the perspective of cultural differences.