Oxaliplatin is an anticancer drug belonging to a new class of platinum compounds in which the platinum atom forms a complex with 1,2-diaminocyclohexane (DACH) and an oxalate group. Oxaliplatin is the only enantiomer of (SP-4-2)-[(1R,2R)-cyclohexane-1,2-diamine-kN, kN’] [ethanedioato(2-)-kO1, kO2] platinum. Oxaliplatin exhibits a broad spectrum of both in vitro cytotoxicity and in vivo antitumor activity in a variety of tumor models, including human colorectal cancer models. Oxaliplatin also exhibits in vitro and in vivo activity in a variety of cisplatin-resistant tumor models. In combination with 5-fluorouracil (5-FU), synergistic cytotoxic effects have been observed both in vitro and in vivo.