This study was aimed at investigating the implementation of the Sufficiency Economy Philosophy of Environment Management in the manufacturing industry and their related factors. A questionnaire was used for 400 manufacturing industries from November 2010 to February 2011. Descriptive statistics, that is means and percentages and inferential statistics, as well as test hypothesis by Chi-square at .05 significance level were used. The results showed that 76.2% of the manufacturing industries studied have a policy of environmental management, although water and garbage pollution were found to be significant. Most of them are highly aware of environmental management. Their perception of the Sufficiency Economy Philosophy was learned mostly from television. In addition, more than half of them, or 60.2%, have a high level of knowledge and understanding of the Philosophy and 44.8% of them have a good attitude toward the Philosophy. The results also showed that key success factors for implementing the Sufficiency Economy Philosophy in environmental management were the vision and policy at the management level, knowledge and understanding of the Philosophy in environmental management and participation of staff, belief in the philosophy, including providing support by involving units and monitoring and assessing by their implementation of the philosophy. A total of 60.2% of them demonstrated interested by their implementation of the Sufficiency Economy Philosophy in environmental management. The results of hypothesis testing showed that factors relating to the implementation of the Sufficiency Economy Philosophy in environmental management in the manufacturing industry depended on the size of the industry, environmental management policy, receiving of information, attitude towards the Sufficiency Economy Philosophy and participation in activities implementing the Sufficiency Economy Philosophy.