Current study was carried out to compare the effects of passion flower hydroalcoholic extract and diazepam on reducing anxiety behaviors of laboratory mice. 60 mature mice from the weight range of 25-30 g were used. Treatment groups were Control, Stress, diazepam, and 50,100 and 200 mg/kg of extract. To enforce the anxiety, mice were placed in a dark box for thirty minutes. After that, each mouse was located in a plus elevated maze and its behavior was recorded. Obtained data were analyzed using SPSS program. Hydroalcoholic extract decreased the presence time of animals in maze arm in 100 and 200 mg groups which indicates the anxiety reduction of these doses. According to results, the extract hadanxiety reducing results similar to diazepam dose dependently.