|This study is a non-experimental, one sample pre-post test, aimed to evaluate the effectiveness of a self developmental program on self-care behaviors and diabetic control in type 2 diabetic patients. Seventy subjects were selected from type 2 diabetic patients who have attended the diabetic clinic at Phosai hospital, Ubonratchathani province, according to the study criteria. The self developmental program included lecture, demonstration, group discussion to exchange experiences, self-care practice according to self-care guideline. In addition, patients were arranged to participate small group meetings every other weeks for 6 weeks. Patients’ self-care behaviors were evaluated at the beginning and the end of the program. Diabetic control was assessed by measurement of the morning fasting blood sugar and body mass index every month, measurement of HbA1c at the beginning and at the end of the program. Patients were participate this program for 17 weeks. Results shows that, at the end of the program, the average score points of total behaviours and of several individual behavioural aspects, including food consumption, medication, foot care, exercise, and general health care were significantly greater than at the beginning of the program (p<0.05). In addition, the outcomes of diabetic control at the end of the program assessed by average fasting blood sugar concentration, HbA1cvalue, and body mass index were significantly lower than at the beginning of the program (p<0.05).