The importance of projects has resulted in increased international standards, academic research, and education and training on project management concepts. However, studies show that the number of successful projects has not changed significantly. As conventional wisdom emphasizes organizational project management maturity, the aim of this research effort is to study the relations between project success and project performance factors, and organizational project management maturity.The results of this study suggest that having a project portfolio management function within the organization improves the likelihood of assigning priority for projects and meeting quality expectations and project objectives. The presence of formalized project management processes may influence the assigning of project priority and the use of project planning tools and techniques. Furthermore, organizations with project policies and procedures in place are more likely to require project managers to have their PMP certification. Results show that customer satisfaction is considered the most important project success factor and more so for organizations with portfolio management in place.