The objective of the present article is the evaluation of the scientific literature on the evolution of operated transsexual people and the consequences of the hormonal and surgical treatments. It seems crystal clear that both treatments produce much more positive effects than expected by the physicians and the psychologists in the past. Together with an appropiated follow-up and a correct assessment of the psychological vulnerability, these elements make acceptable the demand of sex change. Studies on the "psychological risk profile" are necessary to evaluate the factors of further adaptability and also to propose preventive steps at the beginning of the hormonal and surgical treatment.