Purpose: We aimed to investigate the relationship between metabolic syndrome and sexual function and effective parameters on erectile dysfunction (ED). Materials and Methods: A total of 1300 individuals were included in this study between January 2009 and July 2012. All of individuals were asked to fill in an International Index for Erectile Function (IIEF) questionnaire. The presence of metabolic syndrome was determined when any three or more of the five risk factors were present according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP)-III. Obese individuals were divided into six groups according to modified World Health Organization (WHO) definition. Effective parameters on erectile dysfunction were investigated in individuals with metabolic syndrome. Results: Metabolic syndrome was detected in 455 individuals (35%). Mean domain scores of IIEF for all parameters were higher in individuals without metabolic syndrome than individuals with metabolic syndrome (p < 0.05). Mean domain scores of IIEF were lower in individuals with class 3 obesity than individuals with other obese groups (p < 0.05) for erectile dysfunction. There was statistical difference in terms of mean score of IIEF-Erectile function between smoking and nonsmoking groups (p < 0.05). Seventy percent of individuals with metabolic syndrome and 45% of individuals without metabolic syndrome had ED (p < 0.001). Logistic regression analysis revealed that waist circumference (WC) was the most important criteria for ED (p < 0.05). Conclusions: Metabolic syndrome, smoking and obesity seem to be potential risk factors for ED. We recommend individuals with metabolic syndrome, smoking and obesity should be questioned about ED.