The composition of the essential oil obtained by hydrodistillation from Minthostachys mollis Griseb (Lamiaceae) aerial parts was determined by GC and GC/MS. Menthone (13.2%), pulegone (12.4%), cis-dihydrocarvone (9.8%) and carvacrol acetate (8.8%) were the main essential oil components. The cytotoxic activity of the essential oil was in vitro measured using the MTT colorimetric assay. IC50 values were calculated on healthy non-tumor cells (HEK-293) and three human cancer cell lines (T24, DU-145 and MCF-7). In such latter cells, the estimated values were around 0.2 mg/mL. In addition, the antioxidant activity was determined by interaction with the stable free radical 2,2”-diphenyl-1-picrylhydrazyl. The essential oil was almost devoid of antioxidant activity indicating that its anti-proliferative action relies on other unknown mechanism.