Objective. To evaluate the effect of hemantane administered by external application, intraperitoneal injection and combined external and intraperitoneal administration in rats with postoperative pain compared to diclofenac. Material and methods. Mechanical (von Frey test) or thermal (plantar test) hyperalgesia in rats was recorded for 4 days after surgery (longitudinal incisions of skin and flexor digitorum brevis muscle of the hind paw). Hemantane and diclofenac were applied to the paw and/or administered intraperitoneally twice a day on the day of surgery and 3 days after it. Results. Hemantane administered by external application (5% gel), intraperitoneal injection (10 mg/kg) and combined maneuver significantly reduced mechanical postoperative hyperalgesia. The effect of hemantane was superior the effect of diclofenac (5 mg/kg, 1% gel) when administered intraperitoneally or by combined approach. Effect of hemantane and diclofenac gels was similar. Both drugs had no significant effect on thermal postoperative hyperalgesia when administered via external or intraperitoneal route alone. Hemantane and diclofenac influenced thermal hyperalgesia only after topical application and simultaneous intraperitoneal injection. Conclusion. Low-affinity non-competitive NMDA receptor antagonist hemantane reduces mechanical hyperalgesia in rats with postoperative pain when applied topically (5% gel), intraperitoneally (10 mg/kg) or via both routes. Its effect is no inferior to diclofenac (5 mg/kg, 1% gel). Hemantane and diclofenac influenced thermal hyperalgesia only after topical application and simultaneous intraperitoneal injection.