This qualitative study investigates the nature of commitment in long-lasting mixed-orientation relationships, in which a homosexual man is partnered with a heterosexual woman. Previous research into mixed-orientation relationships has generally not focused on which factors contribute to keeping the relationship together. The primary theoretical frameworks used in this study to understand long-lasting, mixed-orientation couples are social exchange theory and Johnson's (1999) commitment model. Thirteen couples from the U.S. completed questionnaires and were interviewed about three main topics: (a) the history of their relationship, including the coming-out process, (b) strengths of the relationship, and (c) challenges to the relationship. The couples also offer advice to other mixed-orientation couples who wish to stay together. Transcripts were coded to illuminate how these mixed-orientation couples remain in committed relationships. Participant comments revealed that there are three essential characteristics of long-lasting, mixed-orientation relationships, which are (a) a high level of personal commitment, (b) open communication, and (c) adaptability.