Micromeria fruticosa L Druce subsp. serpyllifolia is a medicinal herb that is widely used as folk medicine in the treatment of abdominal pains, diarrhea, eye infections, heart disorders, elevated blood pressure, colds and wounds. This study aims to investigation the constituents and biological activity of the essential oil and aqueous extract of the plant that had been collected from Nablus. The oil was prepared by hydro-distillation method and analyzed by GC/MS. The oxygenated constituents were prevalent (87.4%) with the pulegone (58.5%) was the major constituents. Antitumor and analgesic activities of the isolated oil and the aqueous extract of M. fruticosa were investigated. Both the oil and the aqueous extract exhibited marked antitumor activities against Human Colon Tumor cells (HCT) and Mammary Carcinoma F7 (MCF7). The oil showed less IC(50s) against both cell lines (10, 12.7 μg/ml respectively). Also the extract significantly inhibited acetic acid-induced writhing response (p<0.05) and increased hot-plate pain threshold of mice at doses of 100 and 200 mg/kg while the oil did not show any analgesic activity on both models. Therefore, we concluded that the aqueous extract of M. fruticosa has a remarkable inhibitory activity in non-inflammatory reactions as well as inflammatory pain.