The articles in this JSI issue focus on how gender, gender role identity, and attitudes toward gender roles may affect the nature of relationships and how relationships may affect an individual's gender (including, behaviors, attitudes, and self-perceptions). Though the focus is mainly on heterosexual relationships and U.S. samples, research on lesbian/gay and parent-child relationships as well as same-sex friendships and relationships in different cultures are examined. Meanings of commonly used terms in research on gender are clarified and we summarize each article briefly. General themes that emerge from the articles are discussed.