Oxidative stress significantly impairs sperm functions (Emanuele et al., 2001) and the crude extract of Garcinia kola has been shown to reduce fertility in male rats (Akpantah et al., 2003). In this study, the effects of kolaviron, a biflavonoid from Garcinia kola seeds were examined on ethanol-induced oxidative damage in Sprague-dawley rats. 25 adult males were used. These were divided into 5 groups; group 1 served as control, which received corn oil (the vehicle for kolaviron), groups 2, 4, and 5 received kolaviron (100mg/Kg body weight), groups 3, 4, and 5 were administered ethanol (15%v/v body weight). All groups were treated for 4 weeks except group 5, which was treated for 8 weeks. Group 4 was given ethanol and kolaviron simultaneously while group 5 was treated initially with ethanol (4 weeks) and then kolaviron (4 weeks). Sperm morphology, histology and weights of organs, and MDA tests were assessed. Kolaviron, has no significant effect on male reproductive functions, but significantly (p<0.05) attenuated the damaging effects of ethanol on metabolic and reproductive organs as well as sperm functions. The antioxidative property of kolaviron was also confirmed in this study. Kolaviron a natural antioxidant(Farombi et al 2002), may therefore be used in the treatment of male fertility problems associated with oxidative stress damage.