A better understanding of the molecular and cellular mechanisms controlling the immune system in the past two decades has opened the door to many innovative and promising new cancer therapies that manipulate the immune response. For instance, wide arrays of antigen specific cancer vaccines and cell-based immunotherapies utilizing T-cells, natural killer cells and dendritic cells have been established. Furthermore, a rapidly expanding repertoire of monoclonal antibodies and bispecific antibodies is being developed to treat tumors and many of the available antibodies have demonstrated impressive clinical responses. This review briefly summarizes some of these active immunotherapy (vaccination) and passive immunotherapy (antibody-based therapy) currently in use or under clinical investigations that may soon become part of the therapeutic arsenal to combat cancer in a more efficient way.