To investigate postoperative functioning of the first 22 consecutive adolescent transsexual patients of our gender clinic who underwent sex reassignment surgery. The subjects were interviewed by an independent psychologist and filled out a test battery containing questionnaires on their psychological, social, and sexual functioning. All subjects had undergone surgery no less than 1 year before the study took place. Twelve subjects had started hormone treatment between 16 and 18 years of age. The posttreatment data of each patient were compared with his or her own pretreatment data. Postoperatively the group was no longer gender-dysphoric; they scored in the normal range with respect to a number of different psychological measures and they were socially functioning quite well. Not a single subject expressed feelings of regret concerning the decision to undergo sex reassignment. Starting the sex reassignment procedure before adulthood results in favorable postoperative functioning, provided that careful diagnosis takes place in a specialized gender team and that the criteria for starting the procedure early are stringent.