AbstractCopaiba oil, extracted from Copaifera multijuga Hayne, Fabaceae, is widely used for medicinal purposes, especially to treat inflammatory processes. However, there is no report regarding its effect on reproductive performance after used in repeated doses orally. The present study evaluated the effects of the oral administration of Copaiba oil (at doses of 200, 500 or 2500mg/kg) or water (control) for eight weeks in male Wistar rats. Treated males mated untreated females, and parameters as fertility rates, absolute and relative mass of accessory sexual organs and histology and development of the offspring were evaluated. Chemical analysis revealed the presence of 22 components accounting for 99.11% of the Copaiba oil. The main compounds identified were sesquisterpenes. The reproductive toxicology results indicate that there was no difference between the treated groups compared with the control group in any of the parameters, suggesting that the oral treatment with C. multijuga oil for eight weeks does not affect reproductive performance of male Wistar rats.