The antioxidant and antinociceptive activities ofCitrus limonessential oil (EO) were assessed in mice orin vitrotests. EO possesses a strong antioxidant potential according to the scavenging assays. Moreover, it presented scavenger activity against allin vitrotests. Orally, EO (50, 100, and 150 mg/kg) significantly reduced the number of writhes, and, at highest doses, it reduced the number of paw licks. Whereas naloxone antagonized the antinociceptive action of EO (highest doses), this suggested, at least, the participation of the opioid system. Further studies currently in progress will enable us to understand the action mechanisms of EO.