This is the user's manual of MC@NLO 2.0. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix elements consistently into a parton shower framework. The processes available in this version are those of vector boson pair and heavy quark pair production in hadron collisions. This document is self-contained, but we emphasise the main differences with respect to version 1.0.