Mangiferin, 1,3,6,7-tetrahydroxyxanthone-C2-β-D: -glucoside (C-glucosylxanthone), is a xanthone derivative that is widely distributed in higher plants. Recently, mangiferin was found to exhibit potential antitumor effects. However, the molecular mechanisms of this effect have not been elucidated. In the present study, we attempt to clarify the mechanism of mangiferin-induced apoptosis in the human acute myeloid leukemia cell line HL-60; mangiferin was found to induce apoptosis. We also observed a concurrent increase in caspase-3 activity and DNA fragmentation. Furthermore, on examining the survival signals expressed during apoptotic induction, we observed that mangiferin caused a remarkable decrease in the nuclear entry of NF-κB p65. However, there were no changes in the expression of other survival signals, such as extracellular signal-regulated kinase 1/2, protein kinase B, and p38 mitogenactivated protein kinase. In addition, mangiferin suppressed the expressions of Bcl-xL and XIAP; however, we did not note any changes in the levels of Bcl-2, Bax, and Bim. These results indicate that mangiferin induces apoptosis by suppressing NF-κB activation and expressions of Bcl-xL and XAIP. These findings suggest that mangiferin may be useful as an anticancer agent and can be used in combination therapy with other anticancer drugs for the treatment of acute myeloid leukemia.