This chapter presents a case study about applying the Sufficiency Economy Philosophy to a prisoner rehabilitation and development project in Khaw Plong Temporary Prison. It discusses how sufficiency-based education and skills-training programs have successfully guided and supported inmates to live virtuous lives with a sufficiency mindset, both during their imprisonment and after their release. A data-collection process involving inmates and various stakeholders was used to gain an understanding of the project and its efficacy. Findings revealed that after 30 male inmates completed the program, the recidivism rate among participants was only 10 per cent, somewhat below the typical rates of around 14 per cent (Rujjanavet, 2008). The study provides evidence that the rehabilitation and development programs based on the Sufficiency Economy Philosophy positively benefited inmates over the long run, not only by reducing recidivism rates but also qualitatively by allowing them to transform their lives so the became productive members of society.