The diagnosis of transsexualism, which can be called transgender, or gender non-conforming patients, is usually made by a physician in the field of psychiatry. Currently there is no particular standardized scale for the use of diagnostic modalities, unlike the diagnosis of other disorders, which can be obtained through a number of laboratory tests, ancillary examinations, or very obvious physical positive signs. The diagnosis of transsexualism may require more of a thorough communication with the transgender patient or his or her family, to understand the patient’s life and all aspects of it, and to make a preliminary judgment based on the entire process of trans history. It is also possible to use some of the psychological scales currently available, such as the Symptom Self-Assessment Scale, the Anxiety Self-Rating Scale, the Depression Self-Rating Scale, or the Minnesota Personality Assessment Scale, to help with the diagnosis, but none of these are the gold standard for diagnosis. In the future, there may be psychological scales for transgender populations, and through the continued efforts of psychiatrists in the field, appropriate scales will be available early to help patients make a more accurate diagnosis.