To identify emotional and attitudinal barriers to improved glycemic control (HbA1c) during intensive diabetes treatment, 55 patients attending a 4-5 month intensive diabetes medical/education clinic were followed. Subjects completed a battery of psychological surveys, had HbA1c and body mass index measured, and rated their attitude toward weight gain and the extent of problems with specific self-management behaviors before and after the medical intervention. Although HbA1c improved on average, 29% had only modest improvement and 16% showed no improvement. The number of diabetes-related annoyances, worry about hypoglycemia, and diabetes-related emotional distress diminished. Only the satisfaction subscale of the Diabetes Quality of Life survey, diabetes-related emotional distress, and problems with self-management behaviors correlated with HbA1c. Treatment-related frustration and emotional distress may initially act as motivators to improve glycemia but can later become barriers to that goal. Interventions designed to help patients overcome attitudinal barriers should be incorporated into medical programs geared toward improving glycemia.