The course provides knowledge to deal with calculations of biological interest. Principles of biology and chemistry are delivered together with a deep understanding of the methods used to compute chemico/physical properties of molecules such as organic and peptidic ligands, proteins and nucleic acids. Standard and advanced computational techniques are described in details and many applications are illustrated. Molecular dynamics, free-energy calculations are some examples. Great attention is dedicated to the application of these methods in drug design through rational approaches and more automated protocols.