Ruthenium complexes are also important as antitumor agents and some are currently under clinical trials. It follows a novel mechanism of action with the prospect of non-cross-resistance, reduced toxicity and acquires different activity. The Ruthenium complexes are suitable towards cisplatin resistance cancer cells, and efficiently exert antitumor action, which may be in part due to the ability of ruthenium complexes to mimic the binding of iron to certain biological molecules that in fact exploits a mechanism for non-toxic transport of iron inside the body. This property is especially attractive for ruthenium complexes. The ability of ruthenium to mimic iron in binding to certain biological molecules make these complexes well suitable for medicinal use, and as an alternative for the platinum anticancer drugs in the treatment of cancer cells, resistant to cisplatin and its analogues. The water soluble Ru complexes are usually suitable for medicinal use, and several Ru based drugs have shown good anticancer activity.The Ru complexes have certain advantages than the platinum complexes due to its solubility in water and low toxicity.