摘要:AbstractWhen talking about large infrastructure projects one can often hear – “it is a very complex project”. What does it mean? What makes large infrastructure projects complex? This paper is exploring current views on project complexity and its development though history. As part of the research on large infrastructure projects, the perception and elements of complexity was investigated. The research is based on in-depth analysis of large infrastructure projects and project manager's perception of complexity. The result of the paper is proposal of new model of project complexity for large infrastructure projects.