In spite of the potential clinical utility of defense mechanisms in the assessment of gender identity disorder patients as candidates to sex reassignment surgery, there is paucity of research in this field. The aim of the present study is therefore to ascertain whether the defensive profile of MtF and FtM transsexuals seeking sex reassignment surgery can be defined more primitive, immature and maladaptive than that of the two control groups. We compared the defensive profiles as assessed through the REM-71 (Steiner et al., 2001) of 104 MtF transsexuals, 46 FtM transsexuals and two control groups of males and females. Our results show that MtF transsexuals present an overall more primitive defensive array than that of both control groups, while FtMs show a profile not dissimilar from that of both control groups. Our results support the hypothesis that MtF transsexuals are characterized by higher proneness to psychopathology than the general population and show a more immature level of psychological functioning than FtM transsexuals.