Experiences and studies, results and documentations review show that the impress and the stra-tegic level of Project Management (PM) have been increased. Different organizations have in-troduced various standards for PM. Indeed, the main criterion to select and apply PM standards relies on the standard, depending on the project type and the experiences of PM managers. The primary objective of PM standards is to direct a project into a systematic and regular framework. Application of PM standards makes project easier and gives accurate analysis that provide bene-fits for executives and gives some managerial approach. The main purpose of this research is to compare and evaluate two most popular and versions of PM standards; namely PMBOK and ISO 21500.