This work presents a revision of the main definition and significances of the term Intellectual Capital, as it is an important issue of study. Once the main scientific works related to Intellectual Capital are presented and their main contributions highlighted, this work shows how it has been attempted to measure the Intellectual Capital at both individual enterprises and collaborative networks, as a source of meaningful information to make decisions. The paper evidences the lack of works that have successfully dealt with measuring Intellectual Capital at the collaborative networks level, highlighting the main barriers and what a proper measuring framework should address at this level.