Aim. To analyze the types of attitude towards disease, their relationships to its course in patients with diabetes mellitus (DM). Subjects and methods. 418 patients with DM, including 318 with type 2 DM (T2DM) and 100 with Type 1 (T1DM), were examined. Clinical and laboratory examinations were performed; the types of attitude towards the disease were studied. Results. The patients with T2DM were more frequently found to have anxious (12.9%) and hypochondriacal (10.7%) types of attitude towards the disease; those with T1DM had euphoric types. The paranoiac type of disease attitude, which was characterized by the presence of peculiar notions about the disease, was detected in 15.1% of the patients with T2DM and in 13% of those with T1DM. Hypernosognosia (overreaction to disease) was more often identified in T2DM (62.3% versus 39% in T1DM (χ2; p < 0.001). In the T2DM group, hypernosognosia was more frequently seen in women, unemployed persons, and obese patients. With the comparable awareness about the disease and degree of self-control, the patients with T2DM with no signs of hypernosognosia had a lower glycated hemoglobin level [7.35 (6.6; 8.6)%] than those with hypernosognosia [7.9 (7; 9.4)%] (p = 0.024). Conclusion. The revealed peculiarities of attitude towards the disease in patients with DM justify the need for increased attention to their psychological characteristics. The situation could be improved if the physicians are be informed, the time of outpatient care is prolonged, and psychotherapists and/or clinical psychologists are widely involved in the management of diabetic patients.