The word `complex is now being widely used to describe projects which are extraordinarily difficult to manage and control. Are these projects just very difficult or do they exhibit special characteristics that entitle them to be called `complex? Some authors argue that so-called `complex projects are simply larger projects with more stakeholder issues. Nevertheless, there is a growing recognition amongst project practitioners and academics that particular projects seem to be more than just difficult and these projects have very special characteristics that pose extraordinary management challenges. This paper argues that these special projects exhibit aspects in common with `complex adaptive systems. If we accept that some projects behave in very different or unpredictable ways, how do we manage them? This is the practical question at the focus of this paper. Do approaches exist which will assist the practitioner with these special or `complex projects? The paper presents a discussion of project complexity using `complex adaptive systems thinking as a lens. Findings from part of a continuing research program are presented and discusse