Background: The most economical and ecological nature of Prosopis juliflora with its medicinal value in arid and semi-arid zones of the world for its different properties against inflammation, it is a tree, belongs to the family Leguminosae (Fabaceae). Aims and Objectives: To evaluate the analgesic activity of methanolic extract of dried leaves of Prosopis juliflora Linn. Materials and Methods: Adult male Wistar rats (100–150 g body weight) were used in this study. Methanolic extract of Prosopis juliflora Linn was used to evaluate acute analgesic activity by tail flick method by oral administration at doses of 300, and 500 mg/kg body weight in healthy albino rats. Result: In acute studies, the methanolic extract showed significantly and dose-dependently reaction time but after 1 hour the reaction time was absent. Statistical analysis was carried out by one-way ANOVA, followed by Turkey’s test. Conclusion: methanolic extract of Prosopis juliflora Linn possesses analgesic activity in a dose-dependent manner in thermal induced model.