This study examines issues surrounding the sustainability of SMEs in the context of Thailand. Sufficiency economy philosophy and government support are seen as important covariates that could foster sustainable performance of SMEs. A sample of 119 SME entrepreneurs in the South of Thailand participated in this study. Exploratory factor analysis and hierarchical multiple regression were conducted and the results demonstrated that some dimensions of sufficiency economy philosophy and government support are critical predictors of economic and social performance. Moreover, knowledge and morality are found to promote the principle of sufficiency economy philosophy, as such SME entrepreneurs should be cognizant of the potential effects of this philosophy. The appropriate practices can be equipped and nurtured through the values of sufficiency economy philosophy, which shed light on means to achieve firm sustainability.