The National Building Code (NBC) of Nigeria was developed to provide a regulatory framework for ensuring safety, quality, and sustainability in the construction sector. However, despite its critical role, effective implementation of the NBC has been marred by numerous challenges, particularly in the South-South region of Nigeria. This paper investigates the barriers to the successful implementation of the NBC from the perspective of key stakeholders including architects, builders, engineers, government officials, and private developers. Using a mixed- methods approach, primary data were collected through structured questionnaires and in-depth interviews across six states in the South-South region. The findings reveal that challenges are multidimensional, ranging from institutional weaknesses and poor awareness of building standards to economic constraints and enforcement inefficiencies. In particular, the lack of coordination among enforcement agencies, cultural resistance to standardized building methods, and limited training for practitioners are critical issues. Economic hardship and inadequate incentives for compliance also contribute to widespread nonadherence to the NBC. Based on these insights, this paper recommends state-level legislation to domesticate the NBC, capacity building for regulatory agencies, sensitization programs, digital permit systems, and incentive-based compliance models. Tables summarizing the frequency and severity of each identified challenge are included. This research contributes to a growing body of knowledge on building regulation enforcement and provides actionable policy directions aimed at improving building safety in Nigeria. Ultimately, overcoming the identified barriers will require a coordinated, inclusive, and wellresourced approach that recognizes the unique socio-economic and environmental dynamics of the SouthSouth region