Zinc is a trace element, which is abundant in nature. It is also an essential and important micronutrient found in many foods. It has a role in multiple bodily processes including wound healing and boosting of the immune system. This review shows evidence of zinc deficiency in cancer patients of all types, a deficiency that correlates with disease severity and negatively correlates with survival rates. Lower zinc levels led to more severe and advanced disease symptoms and to lower survival rates. Zinc is a nanoparticle and acts as a photosensitizer in photodynamic therapy in various combinations with other substances. It also shows incredible cytotxicity and tumor suppressive ability in studies conducted both in vitro and in vivo as well as in studies conducted in humans. This result is shown in all types of cancer tested. Zinc shows incredible toxicity toward cancer cells without showing any side effects toward healthy cells. It is recommended that zinc be added to cancer treatment regimens to alleviate zinc deficiency in cancer patients and perhaps to treat cancer as a whole