OBJECTIVES: Quality-of-life (QoL) is increasingly recognized as an important outcome measure that provides information on the burden of diabetes on the physical, mental and social aspects of patients’ health. To pick up disease-related changes in QoL of diabetes patients in Korea, we administered Korean Audit of Diabetes-Dependent Quality-of-Life (KR-ADDQoL) instrument.  METHODS: A prospective, observational study was carried out on type 2 diabetic patients from the diabetic clinics of 24 medical centers throughout Korea. A total of 413 diabetic patients aged 40 years and over were assessed for Health-Related QoL (HRQoL). HRQoL was assessed with KR-ADDQoL instrument. RESULTS: Patients with diabetes were 58±9.7 years old (47.2% female), had diabetes for 7.0±6.2 years. The mean present QoL was 0.4±0.97 (range: -3 [extremely bad] to 3 [excellent]) and diabetes-dependent QoL was -1.5±0.98 (range: -3 [very much better] to 1 [worse]). Patients with diabetes and those with hypertension reported lower present QoL, compared with diabetes only (0.3±1.01, 0.6±0.85; p=0.0161). The mean KR-ADDQoL average weighted impact (AWI) score was -2.4±1.8. Patients with 15-20 years of diabetes reported significantly worse AWI scores (-3.7±1.6) compared with those with 10-15 years (-1.9±1.5). A negative impact of diabetes was seen in all the dimensions of KR-ADDQoL. Freedom to eat and people’s reaction remained as the most (mean AWI scores: -4.3±2.8) and least (-1.3±2.1) affected QoL domains, respectively, when weighting was considered.  CONCLUSIONS: Type 2 diabetes has a negative impact in HRQoL in the patients studied. The findings highlighted the impact of diabetes on QoL with particular reference to the effects on freedom to eat, and freedom to drink. Our study contributed to the knowledge of QoL in Korean patients with type 2 diabetes by using a diabetes-specific QoL instrument. These findings suggest that the impact of diabetes in QoL among Asian is similar [ADDQoL AWI score in Singaporeans: -2.6±1.9].