Advances in understanding the mechanisms of cancer cells for evading the immune system surveillance, including how the immune system modulates the phenotype of tumours, have allowed the development of new therapies that benefit from this complex cellular network to specifically target and destroy cancer cells. Immunotherapy researchers have mainly focused on the discovery of tumour antigens that could confer specificity to immune cells to detect and destroy cancer cells, as well as on the mechanisms leading to an improved activation of effector immune cells. The Food and Drug Administration approval in 2010 of ipilumumab for melanoma treatment and of pembrolizumab in 2014, monoclonal antibodies against T‐lymphocyte‐associated antigen 4 and programmed cell death 1, respectively, are encouraging examples of how research in this area can successfully translate into clinical use with promising results. Currently, several ongoing clinical trials are in progress testing new anti‐cancer therapies based on the enhancement of immune cell activity against tumour antigens. Here we discuss the general concepts related to immunotherapy and the recent application to the treatment of cancer with positive results that support their consideration of clinical application to patients.