The purpose of this study was to investigate the dietary behavior of people with type 2 diabetes mellitus and to improve their quality of life through medical nutrition therapy. The subjects were 38 persons with type 2 diabetes mellitus visiting a public health center to participate in a dietary education program from Jun, 2003 to Nov. 2003 in Daegu, Korea. The interviews were tape-recorded and analyzed attitude, knowledge, and awareness of patients by focus group interview. Most of the patients were mainly dependent on drug therapy and had little experience of diet education. Barriers to dietary practice adherences were limitations in food selection, lack of will and feel of burden. Barriers to follow guidelines were lack of self-control, confliction with food habits of their family, accessibility, economical problems, fear for the change after dietary practice, food difficulties in meal distribution and difficulties for eating out. After 4 weeks of intensive nutrition education, fasting blood sugar levels were decreased and postprandial and waist circumference were significantly decreased in all patients and 26.9% of patients were under decreased oral hypoglycemic agent dosage due to improved blood sugar level. dietary knowledge of subjects were greatly improved in such items as dietary intake, saturated fat, HbA1C, ideal body weight, and waist circumference.