Oxaliplatin is widely used as a chemotherapeutic agent for treating unresectable or metastatic gastrointestinal tract cancer, such as gastric cancer and colorectal cancer. The toxic effects commonly associated with oxaliplatin include neuropathy, myelosuppression, hypersensitivity reactions, and chemotherapy-induced hepatotoxicity. However, oxaliplatin-induced hemolytic anemia has rarely been reported in the medical literature. Herein, we describe a case of oxaliplatin-induced autoimmune hemolytic anemia in a patient with metastatic gastric cancer who received biweekly oxaliplatin-based chemotherapy that included fluorouracil and folinic acid. He presented with acute-onset anemia and acute renal failure shortly after the 25th course of oxaliplatin-based chemotherapy. A positive direct and indirect Coombs test and a good response to steroid therapy suggested the diagnosis of autoimmune hemolytic anemia. Afterwards, the patient was switched to an oral 5-fluorouracil agent, TS-1, for further treatment.