The study of the interactions involving metallic complexes with biological macromolecules is of fundamental importance for understanding the mechanism of action of metallodrugs, regulatory mechanisms, and chemical speciation of metal ions in biological environment among others. Modern methods of electronic structure calculation together with modern techniques of computer simulation has been used in our group for the study of interactions involving platinum and ruthenium compounds (with antitumoral and/or interesting photophysics properties) with biological receptors.