© 2015 Elsevier Ltd. Cancer immunotherapy, and in particular checkpoint blockade, is now standard clinical care for a growing number of cancers. Cytotoxic drugs have been the primary weapon against cancer for a long time and have typically been understood because of their capacity to directly kill tumour cells. It is now clear that these drugs are potential partners for checkpoint blockade and different drugs can influence the immune response to cancer through a wide variety of mechanisms. Some of these relate to immunogenic cell death, whilst others relate to changes in antigen-presentation, tumour cell targeting, or depletion of immunosuppressive cells. Here, we review some recent advances in our understanding of the immunological changes associated with chemotherapy, discuss progress in combining chemotherapy with checkpoint blockade, and comment on the difficulties encountered in translating promising preclinical data into successful treatments for cancer patients.