Abstract: Gas-chromatographic analysis, analgesic effect and median lethal dose (LD50) of Foeniculum vulgare Essential Oil (FEO) extract were investigated in mice. In all the experiments mice were tested twice, 30 min before drug administration in the baseline latency determinated and 30, 90 and 150 min after drug administration by tail-flick device. Aspirin (150 mg kg-1, peroral) and Morphine hydroclorure (10 mg kg-1 subcutan) were used as reference drugs. Only isotonic saline solution (0.2 mL, intraperitoneal) was given to the control group. 0.25 and 0.50 mL kg-1 FEO extract were given intra peritoneally to FEO groups. LD50 of the FEO was determined as 1.038 mL kg-1. At the 150th min of the study it is determined that all of the study groups (except Morphine group) had significantly analgesic effect when compared with control group and there was no difference between Aspirin and FEO groups. It was concluded that FEO had statistically significant and same analgesic effect with Aspirin showed at the 150th min of the study.