Mentha pulegium is common known as “poleo” and used for the treatment of diarrhea, headache and cough in Mexican traditional medicine. Organic extracts from aerial parts were evaluated to determine their spasmolytic action on rat isolated ileum test. Hexanic (HEMp), dichloromethanic (DEMp) and methanolic (MEMp) extracts induced a concentration-dependent (0.97 to 1000 μg/mL) antispasmodic effect on spontaneous contractions. DEMp was the most active extract; therefore, spasmolytic mechanism was investigated. This extract (200 μg/mL) induced a significant depression on cumulative concentration-response curve for carbachol and serotonin (P<0.05). Besides, extract decreased and shifted to the right KCl- and CaCl₂-induced contraction curves. Moreover, pre-incubation with chlorpromazine (0.001 mM) shifted to the left the relaxant curve. Pre-treatment with L-NAME (1 mM), papaverine (0.01 mM), teophylline (0.01 mM), TEA (1 mM) and glybenclamide (0.1 mM) did not produced any changed of the relaxant curves of DEMp. Findings indicate that dichloromethanic extract of M. pulegium induced its spasmolytic effect through Ca²⁺-influx blockade, which may explain its traditional use against diarrhea.