The chemical profile, cytotoxic and apoptotic effect, and antioxidant activity were determined of ethanolic extracts of Vitex agnus-castus L. (chaste tree). Ripened fruits and fruitless aerial parts were extracted with ethanol, and the chemical characterization of the extracts was determined by LC/ESI-MS-MS. Twelve compounds were tentatively identified in the extracts. The dose-dependent cytotoxic effects of the extracts were tested on C6, A549 and MCF-7 cells by using MTT assay; inhibition of DNA synthesis, and apoptotic and caspase-3 activation effects of the extracts were determined. The potential antioxidant activities of the extracts were evaluated by in vitro methods such as DPPH and ABTS scavenging activity, reducing power and beta-carotene bleaching assays. The fruit extract showed noticeable cytotoxic activity against MCF-7 cells with an IC50 value of 88 mu g/mL. Both extracts showed similar DPPH scavenging activity comparably with that of the standard.