Top 10 Qualities of a Project Manager What qualities are most important for a project leader to be effective? Over the past few years, the people at ESI International, world leaders in Project Management Training, have looked in to what makes an effective project leader. With the unique opportunity to ask some of the most talented project leaders in the world on their Project Leadership courses ESI have managed to collect a running tally on their responses. Below are the top 10 in rank order according to frequency listed.