The aim of this study was to assess the implications of insulin resistance on the clinical and biochemical profiles of Korean type 2 diabetic patients. 122 patients with type 2 diabetes underwent a short insulin tolerance test to assess insulin resistance. Subjects were classified in tertiles according to ISI (insulin sensitivity index), and the tertile I (the insulin- resistant group) and tertile III (the insulin-sensitive group) clinical and biochemical parameters were compared. Age, waist circumference (WC), systolic blood pressure (SBP), HbA1c, body fat content, and fasting plasma glucose were significantly higher in tertile I than tertile III (all p < 0.05). The frequency of hypertension and family history of cerebrovascular disease (CVD) were greater in tertile I than III (p < 0.05). To evaluate the factors affecting ISI, multiple regression was performed, and age, WC, SBP, HbA1c, and body fat content were found to be independently related to insulin resistance (p < 0.05). Old age, hypertension, central obesity, and poor glycemic control were identified as clinical parameters of insulin resistance in Korean type 2 diabetic patients.