Abstract: The subject of project completion is of global concern to parties that are involved in construction of projects. Poor performance of completion of construction projects is usually characterized by production of low-quality projects, time and cost overruns. Success of a construction projects directly affects how a contractor is perceived since it’s a contractor’s responsibility to ensure that a construction projects is completed as that is how their performance is measured. Thus, the study research was on contractor’s firm structure and its influence on completion of building construction projects.