Objectives: Adiponectin has insulin-sensitizing properties, and high adiponectin levels have been shown to be associated with reduced risk of developing diabetes. Patients with coronary artery disease (CAD) have relatively low adiponectin levels and high prevalence of glucose intolerance. The role of adiponectin in predicting the development of diabetes in this high-risk group has not been determined. The study aimed to determine whether baseline adiponectin levels predict the development of diabetes in a group of patients with CAD and impaired fasting glucose (IFG). Methods: A total of 588 patients who participated in the Bezafibrate Infarction Prevention (BIP) study and who had at baseline fasting glucose of 100-125 mg/dl were included and followed for 6.2±1.3 years. Adiponectin was determined in frozen plasma samples taken at baseline. Results: Of the patients with IFG at baseline, 256 (44%) developed diabetes during follow-up. The patients who developed diabetes had at baseline higher body-mass index, fasting glucose, C-reactive protein, triglycerides, homeostatic assessment of insulin resistance (HOMA-IR) and diastolic blood pressure than patients who did not develop diabetes. Adiponectin levels at baseline were significantly lower in patients who developed diabetes than in patients who did not develop diabetes (P = 0.009, nonparametric Kruskall-Wallis test). An increase of 1 unit of natural logarithm of adiponectin level was associated with a hazard ratio of 0.77 (95% CI, 0.61-0.96) for diabetes development. Conclusion: Patients with CAD and IFG have a very high rate of conversion to type 2 diabetes. Even in this high-risk group, high adiponectin levels are associated with reduced risk of developing diabetes.