The administration of Plumbago zeylanica root (50% EtOH) extract to |intact rats at the dose of 150 mg/kg [body weight for 60 days caused arrest of spermatogenesis. The diameter of seminiferous tubules and Leydig cell nuclei were reduced. The production of spermatocytes (primary and secondary) and spermatids were significantly reduced (P£ 0.001; 83.57%, 89.69% and 69.47% respectively). The total number of immature and mature Leydig cells was significantly decreased (P£ 0.001; 68.62% and 71.14%), where as degenerating cells were significantly increased (58.26%). Decreased testicular cell population reflects contraceptive or antispermatogenic nature of Plumbago zeylanica extract and may be of vital use in fertility control.