Abstract The influence of project management on construction projects anywhere in the world cannot be underestimated as poor project management has grave effects on the stakeholders (clients, consultants, contractors and users) and the projects at large. The aim of this study is to investigate the level of awareness of project managers of their roles on construction projects and determine the deficient project management roles that lead to abandonment of construction projects. The study is survey in nature and uses both questionnaire and interview (confirmatory) to elicit necessary information for the study. The population of the study consists of abandoned building projects in Lagos, Nigeria. Sixty-six 66 questionnaires out of the 80 that were administered on project managers of abandoned building projects were returned and used for the study. Thus, the project managers of public and private abandoned projects were used for the study and the results of the study were analyzed with frequencies, percentages and mean item scores. The results of the study indicate that out of the 16 project management roles identified, project managers are very aware of two and aware of the remaining 14. Also, the study found that deficiency in 13 of the roles had high degrees of leading to project abandonment. The conclusion of the study is that project managers are aware of their roles on construction projects but the roles were not performed on those projects, thus leading to project abandonment. In view of this, the study further concludes that there would be some uninvestigated exogenous factors that are responsible for the non-performance of PM roles on those projects. Hence, the study recommends that further studies into why project managers fail to perform their roles on construction projects should be conducted. The study also recommends that project managers must engage in adequate planning, cost control and resource management to prevent project abandonment Keywords: Project abandonment, Building projects, Project manager, Project management