This study showed that the "socially desirable" presentation for a heterosexual male gender dysphoric is one that emphasizes traits and behaviors characteristic of "classic" transsexualism. Fifty-one homosexual and 64 heterosexual adult male gender patients were administered the Crowne-Marlowe (1964) Social Desirability Scale as well as eight questionnaire measures that tapped various features of the clinical history commonly given great weight in differential diagnosis. The tendency for a heterosexual subject to describe himself in terms of moral excellence or admirable personal qualities was significantly correlated with scores in the "transsexual" direction on all eight sexological measures; for the homosexual subjects, only one correlation was significant. It is argued that the patients most motivated to create a favorable impression on the examiner are likely to be those most anxious to obtain approval for sex reassignment surgery. Because, in this population, the socially desirable presentation is "feminine," it is possible that the differences in the histories produced by transvestites and heterosexual transsexuals are exaggerated to an unknown degree by the motivation of the latter to obtain approval for this operation. The findings do not diminish the important distinction between these groups, but they do suggest caution in interpreting the self-report data that have been used in comparing them.