The present study derives culture development practices among “sustainable” small and medium enterprises (SMEs)that adopt the Thai philosophy of the sufficiency economy. It adopts multiple data collection methods including non-participant observations made during visits to five “sustainable” enterprises, and references internal and published documents among other information about the case enterprises, including annual reports, previous studies about the companies and news reports. In-depth interview sessions were held with top management team members and employees, including CEOs or MDs, and division/functional heads. The “grounded theory” is adopted as an approach to analyze the data. The analysis reveals six emerging organizational culture development practices: identifying virtues, social and environmental responsibility and innovation as core values; leaders acting as models according to these values; growing their own managers to continue their corporate cultures; designing communication channels to emphasize the core values among employees; using the core values as criteria to recruit new employees; avoiding employee layoff to preserve the core values even in times of financial crisis. Limitations and future research directions to develop a behavioral theory of sustainability culture in organizational settings, as well as managerial implications are discussed.