The aim of the present study was to determine the effect of orchid bulbs on the reproductive system of male albino mice. Orchid bulb extract was fed to 20 male albino mice (5 g/mouse/day) for 35 days and compared with a similar number of mice as controls. Total testicular germ cell population, histometrical parameters, serum blood biochemistry and hormonal assay were determined. The ingestion of orchid bulb by mice induced a significant increase in the following parameters: (i) testes and seminal vesicle weights; (ii) number of different testicular germ cell population including interstitial Leydig cells and fibroblasts; and (iii) testicular cell linage dynamics obtained from testes and cauda epidydimides. An important finding was that the ingestion of the orchid diet by male mice increased their fertility. This was indicated by an elevation in the number of impregnated females when allowed to mate with treated mice, an increase in the impregnation sites, and an increase in the number of viable fetuses and the offspring's male/female ratio. A slight significant increase in the testosterone and follicular stimulating hormone titers in the treated mice were found in their blood serum. In contrast, a decrease in the number of degenerating cells was observed. Orchid bulb treatment might play an important role in improving male reproductive potential and fertility. (Reprod Med Biol 2006;: 269-276).