Despite the application of project management tools and techniques in projects worldwide, still a large number of projects fail to meet their objectives. Based on studies on the history of failed projects, it is obvious that projects do not result in failure overnight. With hindsight, project managers are often able to point out the most likely factors leading to project failure. One approach towards prevention of project failure or deviation from the main goal is to attempt to detect possible signs of project failure in early stages of projects. These signs are referred to as Early Warning signs. The challenge for project managers is to identify these signs and attempt to respond to them in order to prevent the negative circumstances. Although it is not a proven fact that identification of EW signals is a guarantee against project failure, there are a number of resources which consider paying attention to these signals and attempt to respond to them as a contribution to project success. This book provides better understanding of the Early Warning phenomenon, possible approaches for identifying them and the barriers against effective responses to these signs in practice.