Studies have shown chemopreventive and/or chemotherapeutic effects of several curcumin-based combinatorial treatments on colorectal cancer cells. However, their in vivo effects remain unclear. This study has demonstrated the therapeutic effect of curcumin and oxaliplatin, alone or in combination, on subcutaneously xenografted LoVo human colorectal cancer cells in immunodeficient (nu/nu) mice in vivo. Combinatorial administration of curcumin and oxaliplatin evidently inhibited the growth of colorectal cancer in nude mice, which was significantly more effective than either agent alone. Curcumin combined with oxaliplatin treatment induced apoptosis, accompanied by ultrastructural changes and cell cycle arrest in S and G2/M phases. Further mechanism analysis indicated that while the number of apoptotic tumor cells and the expression of Bax, caspase-3, and poly (ADP-ribose) polymerase (PARP) increased significantly, the expression of Bcl-2, survivin, HSP70, pro-caspase-3, and pro-PARP were dramatically suppressed in tumor cells after the treatment with combinatorial curcumin and oxaliplatin for 22?days. Taken together, the present study has demonstrated that administration of combined curcumin and oxaliplatin effectively suppressed colorectal carcinoma in vivo through inducing apoptosis and thus may provide an effective treatment for colorectal carcinoma.