Industries play vital roles in nation's socio-economic development, and building construction industries constitute an integral path in the Nigerian industrial sectors. Thus, corruption is a social factor associated with the existence of mankind, as it strives to manifest itself when not prevented in every human activity that involves monetary encouragement. Corruption is one of the major negative phenomena in the construction industry that requires sustainable remedies. Therefore, this study investigates the variables that are associated with building construction processes ranging from tendering, construction stage, handover, post-occupancy, and maintenance to the corruption phenomenon that was regrouped into five basic corruption constructs [government influence and bureaucracy, unethical professional practice, client discretional opinion and control, societal greed, and project contractual types] in the Nigerian building construction industries. One hundred and twenty (120) structured questionnaires were administered to building construction professionals [architects, civil engineers, quantity surveyors, service engineers], government agencies in public building units, building contractors and related agencies, and individuals in the field of building construction industries across Ondo and Ekiti State, Nigeria. The collated data was analyzed using Structural Equation Modelling (SEM). Thus, government influence and untidy bureaucracy, societal greed, unethical professional practice, and the unguided imposition of clients' discretionary opinions on building construction projects constitute the major factors responsible for corruption in the building construction industry, as evidenced by our findings. In contrast, project contractual types and their indicators exhibit fewer challenges compared to other corruption factors. This study proposes remedies to address the findings and gives recommendations for achieving corruption-free building construction in Nigeria.