Eugenol, the most important component of clove plant (Eugenia Caryophylata) extract, has been widely used as a local reliever of pain and inflammation. The purpose of this study was to investigate the effect of intrathecal eugenol on thermal pain in male rats. In this research, 27 male Wistar rats, weighing 225±35g were divided into three groups (5, 10 and 15 μl). Lumbar intrathecal catheters were implanted under anesthesia. Five days later, different volumes of eugenol (5, 10 and 15 μl /rat) were administrated intrathecally and the withdrawal tail responses to high temperature (52oC) of water (tail immersion) at different time intervals (pre-catheterization, pre-administration, 10 and 30 min and also 3, 6, 12, 24 hours after eugenol administrations) were evaluated. Eugenol induced analgesia dose-dependently. Furthermore, eugenol at higher doses induced longer analgesic effect. Higher doses of eugenol caused long term paralysis and immobility. The observed analgesic effect of intrathecal eugenol can be helpful in the clinically use of it at the future.