Sex therapy refers to the mental health treatment of physical and emotional concerns related to sexuality and sexual behavior. Although use of the specific designation sex therapist requires specialized training and certification through the American Association of Sexuality Educators, Counselors and Therapists (AASECT), marriage and family therapists (MFTs) are legally able and, with appropriate training, clinically well-prepared to attend to the sexual issues of their clients, even without certification. This entry provides a discussion of the various issues addressed during sex therapy, and it details some of the orienting ideas, interventions, and treatment goals of different sex therapy approaches. It concludes with a list of recommendations for when MFTs should make referrals to medical professionals.