[en] Cancer therapy still faces great challenges in terms of effectiveness, toxicological aspects, and in relation to the triggering factors of resistance, that is, the evolutionary frame of the disease still requires numerous research that solves several problems pertinent to its treatment, thus enabling the improvement in the quality of life of bearers of benign or malignant tumors. For this reason, the development of drugs capable of combating this disease is always presented as a highly important alternative, since currently, available chemotherapeutic agents trigger a series of side effects and consequent resistance phenomena such as Multi Drug Resistance (MDR). In this context, ruthenium complexes emerge as new therapeutic proposals with a favorable toxicological aspect (less toxicity) when compared to other metallo pharmaceuticals with the same functionality. Therefore, this review article presents historical aspects of ruthenium complexes, the main studied examples that entered in clinical phase, their biological mechanisms (antitumor and antimetastatic actions), and perspectives. (author)