Moringa oleifera Lam. or Drumstick tree, a plant in a family of Moringaceae, is widely cultivated in Thailand. Both leaves and fruit of this tree are edible. It is believed to be miracle herbs because it can be used not only as food but also as medicine which can numerous ailments. The leaves of M.oleifera have been used as used as antiulcer, diuretic, anti-inflammatory and for wound healing (Kirtikar and Basu, 1935; Caceres et al., 1992; Udupa et al., 1994; Pal et al., 1995). Moreover, it has been used to enhance male sexual functions including libido, improve sperm quality and anti-erectile dysfunction. Nowadays, numerous health products of M.oleifera are available in the market and claimed for the effect on male sexual functions as mentioned earlier, no scientific evidence was observed until now. Therefore, the current study aimed to determine the effect of M.oleifera leaves extract on male sexual behaviors and the possible underlying mechanism in sexual dysfunction rats induced by stress.