Successful implementations of domestic public construction projects have been increasingly concerned with the efforts to improve the inefficient execution. However, the existing factors causing the inefficient execution have been repeatedly occurred in many projects. This is because the previous studies have been concentrated on identifying the factors without in-depth analysis and systematic prioritization. This study has clarified the characteristics of the inefficient public construction projects, identified the causes, constructed their hierarchical structure, and analyzed the impacts on them. In particular, the critical factors causing the inefficient execution are prioritized by the outcomes derived from the questionnaire surveys, which is limited to the pre-construction stage. They are utilized in prioritizing the institutional and political improvements. However, in the future, the analytic and detailed guideline for remedying the factors causing the inefficient execution of a project should be studied, and their analysis will be extended to the construction stage.