We conducted an empirical analysis to verify the relationship between companies’ ownership structures and earnings management. Our sample included 480 nonfinancial companies listed on Vietnam’s Ho Chi Minh Stock Exchange and Hanoi Stock Exchange from 2012 to 2017, and our explanatory variables included several ratios, such as the controlling shareholders’ stake, management ownership stake, state-owned stake, and foreign ownership stake, which represent different ownership structures. We examined the effects of these ratios on earnings management. Our results suggested that earnings management has a significant linear relationship with the state-owned and foreign ownership stakes. Our results can enhance the understanding of the role of companies’ sustainable ownership structures in limiting earnings management, and they can contribute to future studies of the relationship between earnings management and corporate social responsibility and sustainability reporting assurance practices that focus on corporate ownership structures.