In this study, we surveyed the self-care behavior of 42 diabetics. The motivation to see a doctor was enhanced by occasional symptoms and discomfort secondary to symptoms. The rate of discontinuing self-care behavior in patients increased presumably due to lack of symptoms, ineffectiveness of treatment and burden for complicated treatment modality. Self-control during diet therapy was more difficult for male patients compared with female patients. Patients over 40 years old tended to depend on their family for diet control, and more than 60 years old had a high rate of loss of self-control. Patients believing in the success of self-control ascribed it to their effort, and those who failed in self-control ascribed it to difficulty of the subject. After five years of disease history, the number of patients feeling failure of self-control increased.