Abstract— Recent research has shed new light on individual development during the early adulthood years, yet few investigators have examined sibling relationships during this stage of life. These relationships undergo transformations as individuals enter adult roles and orient their lives toward friends and romantic partners and establish independence from parents and siblings. This article examines major life events and role transitions, such as leaving home, completing school, obtaining employment, getting married, and having children, that influence individuals and their sibling relationships. In addition, it considers how sibling relationships may affect individuals during the transition to adulthood and calls attention to the importance of family and cultural contexts in shaping these relationships. The article concludes with suggestions for future research on sibling relationships during early adulthood and beyond.