We examined the effect of project team culture on the evolution of project team potency in a sample of 110 project teams. Little is known about the factors responsible for the development of project team potency - the collective belief of a project team that it can be effective. Results revealed that project team culture is related to project team potency, and that project team potency is related to project success. Our findings provide project leaders with a tool on how to enhance project success by influencing project team potency, through a change in project team culture