Knowledge is the most important resource needed for project management. The aim of this article is to present a full, consistent model of project knowledge management. There are two basic types of project knowledge: microknowledge, needed for performing a single task (or its part), and macro-knowledge (in other words, all the knowledge possessed by people from a given organizational level). Project knowledge is managed at four distinct levels: individual, project, organization, and global. The article describes the micro-knowledge life cycle and macro-knowledge life cycles from each organizational level, as well as the processes of vertical knowledge flow between organizational levels.