Extracts of Artemisia asiatica Nakai (Asteraceae) possess anti-inflammatory and antioxidative activities. Eupatilin (5,7-dihydroxy-3',4', 6-trimedioxyflavone), one of the pharmacologically active ingredients derived from A. asiatica, was shown to induce apoptosis in human promyelocytic leukemia (HL-60) cells. In the present study, we examined the ability of eupatilin to induce apoptosis in human gastric cancer (AGS) cells. Eupatilin induced the apoptosis of AGS cells as revealed by a decrease in the ratio of pro-apoptotic Bax and anti-apoptotic Bcl-2, as well as the cleavage of caspase-3 and poly(ADP-ribose)polymerase (PARP). The pro-apoptotic effects of eupatilin were further verified by its perturbation of the mitochondrial transmembrane potential (Delta Psi m). In addition, eupatilin treatment led to an elevated expression of p53 and p21. Eupatilin inhibited the activation of ERK1/2 and Akt, which are important components of cell-survival pathways.