Mitochondrion being an organelle plays a major role in many metabolic and bio synthetic pathways. Cancer is strongly associated with changes in cellular metabolism, with a characteristic metabolic shift toward aerobic glycolysis in transformed cells. The recent resurgence of interest in the study of mitochondria has come into the light due to recognition of the fact that the genetic or metabolic alterations in this organelle are causative or contributing factors in a variety of human diseases including cancer. A variety of mitochondrial dna mutations are caused by oxidative damage via ROS that are generated either endogenously during oxidative phosphorylation or by exogenous sources and other mutagens. The ability of adaptation of mitochondrial function has been recognized as crucial to the changes that occur in cancer cells. Due to the presence of this unique property of abundance and homoplasmic nature of mitochondria it makes mt DNA an attractive molecular marker of cancer. These alterations in mitochondrial structure and function might prove clinically useful either as markers for the early detection of cancer or as unique molecular sites against which novel and selective chemotherapeutic agents might be targeted. This review suggests that mitochondrion is one such target.