Diabetes is a chronic metabolic disorder that disturbs the quality of life (QOL) of patients. Therefore, evaluation of diabetes- related QOL could be a key outcome measure for its management. This study assessed the QOL in type 2 diabetes mellitus (T2DM) patients using the World Health Organization (WHO) quality of life (QOL)˗BREF questionnaire and disease-specific appraisal of diabetes scale (ADS). In this cross-sectional study, 520 T2DM patients were included. Patients’ demographic data, clinical information was collected through interviews, and the WHOQOL-BREF instrument and ADS were used for the QOL of patients. Statistical analysis was performed by using R software (Version 3.6.0). The mean ADS scores were lower in controlled diabetic subjects (18.50±3.08) and higher in uncontrolled diabetic subjects (19.29±2.73) (P<0.05). For WHOQOL-BREF, the mean scores for all the domains (overall general health, physical, psychological, social, and environmental) were significantly higher in controlled diabetic subjects (P<0.001). In addition, the age, duration of diabetes, associated comorbidities, treatment, and HbA1c level of patients showed a highly significant correlation with WHOQOL-BREF (P<0.001). Diabetic patients had poor-to-average QOL. Therefore, public health measures and education of diabetic patients are essential to create more awareness for improving the QOL of T2DM.