Background: The purpose of this study was to investigate whether the histopathology of the male transsexual's testis could provide insight into the causes of male transsexualism. Hence, the present study is to planned to investigate significant tissue changes in the male transsexual's testis via histopathological analysis. Materials and Methods: Light microscopy was used to examine histological sections of testicular tissues taken during sex reassignment surgery from phenotypic male transsexuals (n=50, average age range: 39 years) with XY sex chromosomal constitution. The patients had been receiving feminizing hormone (oestrogen) therapy for two to three years when their diagnoses were made based on clinical and psychological data. Results: The fifty participants' notable histological findings included: (i) Spermatozoa with maturation basement membranes and tubular atrophy; and (vi) seminiferous tubules; primarily displaying sertoli cells with cytoplasmic vacuolization and maturation arrest. Conclusion: The current study, propose that refractoriness to oestrogen and the iatrogenic effects of oestrogen superimposed on normal or altered hypoathalamo-pituitary function are the causes of the observed histological characteristics.