Background/Aim. Through its various activities, World Health Organization (WHO) contributed to increasing the understanding of the concept of quality of life. People with diabetes have a lower quality of life than people without chronic illnesses. The aim of this study was to examine the differences in the quality of life, related to health, in patients with diabetes mellitus (DM) type 2 by age, gender and type of therapy. Methods. We performed a cross-sectional study at the outpatient department of the Clinical Center in Novi Sad and the Health Center Ruma - General Practice. The group consisted of 90 patients with DM type 2, 41 men and 49 women. The age of respondents was from 40 to 80 years and they were classifed into four groups according to the ten-year age intervals. We applied WHO Quality of life questinnaire - BREF 100 composed of four domains: physical health, psychological health, social relationships and environment. The general questionnaire asks questions about socio-demographic data, duration of diabetes, the last value of blood glucose and glycosylated hemoglobin, training for self-control and its implementation, informing patients about their disease, therapy and its impact on daily activities and the presence of comorbidity. In statistical analysis the following tests were used: Student’s t-test, Ftest, ANOVA (one way). Results. The average duration of DM type 2 was 11.2 ± 9.2 years. Most of the patients (76%) were trained to self-control and 91% received enough information about their disease. Oral hypoglycemic preparations were used by 49%, insulin by 21%, and oral drugs and insulin by 29% patients while 1% were on a special regime of a diet therapy. Daily activities were performed without difficulties by over 29%, with some difficulties by 41% and 30% of patients who could not perform daily activities. The patients with DM type 2 had significantly lower scors in all 4 domains of quality of life (physical health, psychological health, social relations, environment). The biggest influence was on physical domains (51.31). Education level had an impact on physical and psychological domains. Comorbidity was found in 83% of the respondents. The most common were: arterial hypertension (63%), chronic cardiovascular disease (46%), neuropathy (23%), impaired vision 24%, elevated blood lipids (39%) and amputation of toes or feet (2.2%). The average value HbA1C in the group with comorbidity was 8.47% and in the group without comorbidity 6.46%. The subjects with comorbidity had low quality of life assessment in relation to the group without comorbidity: the domain of physical health (45.64 vs 79.66), psychological health (50.3 vs 76.86), social relations (52.97 vs 75.46) and environment (52.7 vs 75.06). Conclusion. Diabetes mellitus type 2 has negative influence on the quality of life. It contributes to the presence of comorbidity. The occurrence of comorbidity was associated with higher glucosylated HbA1C values. There was no difference in the assessment of quality of life regarding gender, age, or the type of therapy used. The quality of life was assessed as low in patients with comorbidity. However, certain personality characteristics play a decisive role in self-evaluation.