Increased stromal amount was evident in the neonates of BPA treated animals. It was revealed to be significantly higher than in the control. Also, proliferation of prostatic epithelial and stromal cells was detected from the significant increase in Ki-67 immunolabelling. In addition, proliferation of epithelial cells was detected by the increase in AgNORs dots in nuclei of epithelial cells of prostates of BPA treated animals when compared to control.Ultrastructrual study of group I revealed that in control subgroups, the basement membrane of prostatic acini was surrounded by a single layer of fibroblasts that separate the basement membrane from SM cell layer. On the other hand in neonates of BPA treated animals, this cell layer was transformed into several layers of fibroblasts which physically separated the SM cell layer from the epithelium. In addition a significant amount of collagen fibers could be seen in between the fibroblasts of this zone.