Transvestitism, like all true perversions, is not a symptom but a diagnostically distinguishable condition with an exceedingly complex structure which has characteristic features. At the core of this structure is the sexualization of the intense aggression arising from conflicts and frustrations related to the wish for complete union with the original object and this colours all aspects of the transvestite's mental make-up. When the treatment arrives at the point where the patient begins to undo his sexualization so that aggressive feelings, in all their intensity, begin to emerge, the severity of his reactions endangers the treatment and perhaps even the patient's mental integrity. The resultant determined use of the deceptive functions of transvestitism to defend himself further impedes treatment. Throughout the treatment, the analysis of the transference relationship is hindered by the patient's need to keep at a safe distance the gratification of his fundamental wish for 'envelopment'.