Project management is a discipline that has evolved over time through different organizations and / or associations that have developed their own guidelines, bodies of knowledge, books and documents, in some cases being complementary to discuss several aspects. After the recent publication of ISO 21500:2012 - Guidelines for project management has started a way in search for standardization of this discipline. This document reflects a critical analysis of the recent ISO 21500:2012 standard published in the attempt to collect the most important considerations, as well as the similarities and differences between this standard and the different guides available before its appearance. Among the conclusions and future lines of work highlights the approach to raise the possibility of certification, which implies the need for the implementation of project management processes that enunciates ISO 21500:2012. Keywords: Project Management, Project, methodologies, comparison, standard, certification, ISO 21500, processes.