Gender identity disorder (GID), or transsexualism as it is more commonly known, is a highly complex clinical entity. Although the exact aetiology of GID is unknown, several environmental, genetic and anatomical theories have been described. The diagnosis of GID can be a difficult process but is established currently using standards of care as defined by the Harry Benjamin International Gender Dysphoria Association. Patients go through extensive psychiatric assessment, including the Real Life Experience, which entails living in the desired gender role 24 h a day for a minimum period of 12 months. The majority of GID patients will eventually go on to have gender realignment surgery, which includes feminising genitoplasty. The clinical features, diagnostic approach and management of male-to-female GID in the UK are reviewed, including the behavioural, psychological and surgical aspects.