Oxaliplatin-based chemotherapy is recommended as the first-line therapeutic regimen for metastatic colorectal cancer. However, long-term and repeated oxaliplatin therapy leads to drug resistance and severe adverse events, which hamper its clinical application. Thus, chemosensitizers are urgently required for overcoming oxaliplatin resistance and toxicity. Here, the anticancer effects of oxaliplatin combined with piperlongumine (PL), a molecule promoting reactive oxygen species (ROS) generation, in colorectal cancer, were assessed.