Since the introduction of cisplatin in cancer therapy, metal complexes and organometallic compounds have been gaining growing importance in oncology.The impressive clinical effectiveness of cisplatin is limited by significant side effects and the emergence of drug resistance. Thus, novel classic and unconventional PtII and PtIV complexes have been introduced in therapy or are presently in advanced clinical trials.Moreover, innovative non-platinum metal-based antitumor agents, whose activity does not rely on direct DNA damage and may involve proteins and enzymes, have been developed.Gold and tin derivatives are enjoying an increasing interest and appear very promising as potential drug candidates