SUMMARY Prevalence of the Metabolic Syndrome in an Internal Medicine Outpatient Clinic Metabolic syndrome is a major global health problem and its prevalence has been increasing all around the world. People with the meta-bolic syndrome are at increased risk of developing cardiovascular dis-ease. In this study we aimed to determine the prevalence of metabolic syndrome among patients attending to our outpatient clinic. National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP III) was used to categorize a total of 1512 patients (317 men, 1195 women) aged 18-80 years by presence of metabolic syndrome. The prevalence of metabolic syndrome was 27.4% and 43.3% in men and women, respectively. As the prevalence of metabolic syndrome is high among outpatient clinics, it is important to screen patients who have one or more components of metabolic syndrome, for the others.