Project portfolio management (PPM) relies on rankings of projects, which can be challenging due to the many factors and people involved. Project prioritization is essential when a business works on multiple projects simultaneously (whether the projects are wholly independent or interdependent). Managing the projects already in the company’s portfolio and selecting new ones to add to the portfolio are among the essential tasks for many companies. The organization must prioritize the proper initiatives within its diversity to attain its goals and objectives. The ranking approach is a way to prioritize the projects by placing them in order from most important to least important by assigning each task a rating based on a set of criteria. These can be very diverse and depend on many factors, such as different financial and non-financial impacts). This study aims to provide a comprehensive assessment of the existing literature on studies in project portfolio management ranking, focusing on the ranking criteria employed and identifying the journals that published the papers we selected for this analysis. Before ranking, it is necessary to specify which criteria are most relevant to suit the organization’s goals. This research presents the main applicable criteria for ranking project portfolios and their sub-criteria to understand the potential of PPM better, leading to selecting more suitable and valuable projects for the organization. Based on this review, exploring the criteria used for the process, identifying the possibilities for their application, and gaining further knowledge of them enable better portfolio management for the company.