Therapists, having recently come to terms with treating gay and lesbian clients, now must consider the issues that bisexual clients face. This article reviews the literature on what it means to identify as bisexual in a world where sexual identity is viewed as dichotomous, heterosexual at one end and gay or lesbian at the other end. The article explores sexual identity and its biological versus social origins, internalized biphobia, coming out, relationship patterns, and therapist issues. Two cases illustrate issues that might arise when a therapist is treating a bisexual client. The first case is a 17-year-old young woman who is accepting of her bisexual identity, and the second case is a 56-year-old woman, heterosexually identified and married, who suddenly fell in love with a woman. Concluding remarks focus on some future directions for research and work with bisexual clients.