Several natural compounds are traditionally used in popular medicine. Many have shown antitumor and antioxidant properties. Brazilian green propolis is a natural compound widely used by the population and has been shown to act as an effective anti-free radical agent, DNA protector and immune system stimulant. Thus, the present study evaluated, through morphometric, stereological and biochemical analyses, the effect of green propolis on rat’s ventral prostate. 24 Wistar rats were used, distributed equally in 2 groups: C (control), P (propolis). The control group received distilled water (0.5 mL), whereas the treated group received green propolis (6mg/kg/day), both by gavage. The animals received commercial rat chow and water ad libitum and after 56 days, the animals were euthanized, the ventral prostate was collected, weighed and processed for histological analysis. Subsequently, it was photographed with a camera attached to a light microscope (Olympus BX-40). Morphometric and stereological analyses were performed in IMAGE PRO PLUS 6.0 software. Blood was collected in a vacuum tube (Vacuette) with a separator gel and centrifuged for serum separation, the samples were kept under refrigeration (2 to 8°C) until analysis. Total serum PSA and testosterone levels were measured by the ELISA technique. All statistical analyses were performed with PRISM 5 STATISTIC Program. No significant differences of PSA hormone or ventral prostrate weight were found for the groups evaluated. These results are consistent with the measurement of testosterone levels, which also were not significantly altered. Stereological evaluation showed a significant reduction of the volumetric ratio (%) of Muscular Stroma and Epithelium observed by comparison of the groups. Thus, it can be affirmed that the treatment with green propolis used in this experiment significantly affects rat’s prostatic tissue, and therefore can cause reproductive abnormalities in males.