Lemon balm (Melissa officinalis, Laminaceae) is used by people in many regions for relieving toothache, fevers, colds, hyperthyroidism, depression, mild insomnia, epilepsy, and headaches. This study investigated the antinociceptive effect of the essential oil of Melissa officinalis (MOEO) in various experimental models. The median lethal dose (LD50) of MOEO was estimated using the method of Lorke. The antinociceptive effect was assessed using chemical (formalin and acetic acid) and thermal (hot-plate) nociceptive tests in rats. In all experiments, MOEO was administered intraperitoneally at the doses of 10, 31.6, 100 and 316, 1000 mg/kg. In the acute toxicity test, the value of estimated LD50 for MOEO was 2250 mg/kg. MOEO at test doses (10, 31.6, 100, 316 and 1000 mg/kg, i.p.) significantly reduced in dose dependent manner (p < 0.05) the pain response in all tests. Naloxone failed to antagonize the antinociceptive effect of the essential oil in all tests. It seems that mechanism(s) other than opioid receptors is (are) involved in the analgesic effect of MOEO. This study reported the peripheral and central antinociceptive activity of the MOEO and rationalized the traditional use of the plant in the treatment of different painful conditions.