Complexity, an intuitively understood concern for project management practitioners, is often associated with the difficulty of managing projects. The literature suggests that many contemporary projects tend to display the dimensions of complexity such as multi-variance, non-linearity and emergence. Researchers have also proposed multiple frameworks and methodologies to define, identify and measure project complexity. However, the adoption of these frameworks by practitioners is hindered by the lack of a reliable means to classify projects based on their complexity in a practically useful way. This paper aims to address this gap by proposing an approach to identify indicators of project complexity. This approach allows project managers to identify potential causes of complexity in the planning phase of a project with an understanding of the areas of vulnerability. Moreover, they would be able to foresee how complexity manifests during the execution phase of a project and act upon to deal with associated challenges through proactive and reactive measures.