This study investigates the impact of corporate accrual quality (CAQ) on the cost of debt within the highly leveraged construction and real estate sectors of Vietnam. Employing the modified Dechow and Dichev (2002) model to assess CAQ, the analysis utilizes Fixed Effects and System GMM estimators on a comprehensive panel dataset of 252 listed companies (1,630 annual observations) across the HOSE, HNX, and UPCoM exchanges, covering an effective regression timeframe from 2017 to 2023. The empirical findings reveal a strong negative correlation between CAQ and the cost of debt, confirming that creditors penalize low accrual quality by demanding greater risk premiums. Importantly, this study identifies a pronounced regulatory heterogeneity effect: enterprises listed on the strictly regulated HOSE benefit significantly from superior CAQ through reduced borrowing costs, whereas this cost reduction effect completely dissipates in the less transparent environments of the HNX and UPCoM. Consequently, the research provides critical implications for regulators enhancing financial stability, lenders refining credit risk assessments, and corporate managers strategically seeking to minimize the cost of capital.