This research explores the importance of environmental management accounting practices in businesses. It examines how market competition, environmental unpredictability, organizational size, and corporate governance influence the adoption of environmental management accounting tools and environmental performance. Data were collected from a survey of 397 individuals across various industries in Vietnam. The study found that greater environmental unpredictability, more intense market competition, larger organizational scale, and more effective corporate governance promote the use of environmental management accounting, leading to improved environmental performance. Additionally, environmental management accounting methods mediate the relationships among market competition, environmental uncertainty, organizational size, corporate governance, and environmental performance. This study contributes to the literature by highlighting the significance of environmental management accounting practices in Vietnam and offers practical insights for corporate leaders in developing countries. Overall, the findings suggest that businesses in competitive and unpredictable environments should prioritize the implementation of environmental management accounting practices to improve their environmental performance. This has practical implications for corporate leaders in developing countries like Vietnam, emphasizing the need for robust accounting practices to navigate environmental challenges.