Based on retrospective reports of adult males who want to change sex, we have identified preadolescent boys at high risk for the development of adult transsexualism. These boys prefer the dress, toys, activities, and companionship of girls, and state their wish to be girls. During the past four years we have treated five very feminine boys and their parents. Treatment consists of developing a close relationship between a male therapist and the boy, stopping parental encouragement of feminine behavior, interrupting the excessively close relationship between mother and son, enhancing the role of father and son, and generally promoting the father's role within the family. Results indicate the capacity for gender role preference in the preadolescent male to undergo considerable modification toward masculinity.