Abstract: Chemotherapy has been the cornerstone of cancer treatment for decades. However, albeit remarkable, the response to chemotherapy is generally short-lived. With deepened understanding of cancer immunology, resurgence was recently witnessed in the field of cancer immunotherapy. Unlike chemotherapy, immunotherapy induces a relatively mild but stable response. Accumulating evidence reveals that apart from chemotherapy's direct cytotoxic activity, chemotherapy exerts immune-potentiating effects by increasing the immunogenicity of tumor cells or by disrupting the tumor-induced immunosuppression and altering the immune microenvironment. The latter mechanism serves as the basis for the combined use of chemotherapy and immunotherapy. In this review, we examine the rationale for combinatorial therapy in accordance with the current understanding on tumor immunity and newly discovered immune-based chemotherapeutic mechanisms. We further discuss the available preclinical and clinical studies on the combination of chemotherapy and immunotherapy for cancer treatment. We aim to provide a framework for further research.