Recently there is a great advance in anti-colorectal cancer treatment. Several molecular targeting agents, mostly are antibody drugs, are playing an important role. It has recently been proven that new approaches using antibody to immunological checkpoints are effective against certain types of cancer. This is one of the reasons why cancer immunotherapy is now focused in the clinics. In this chapter, several effective immunotherapy against cancer are shown and discussed. Among several types of cancer immunotherapy, immunological cell therapy including lymphokine activated killer (LAK) cell, cytotoxic T lymphocytes (CTL), gamma delta T cell and dendritic cell therapies are reviewed. Major mechanisms that disturb cancer immunotherapy such as escape mechanisms are also discussed.