Aims:Erectile dysfunction (ED) is a common condition affected by many factors. We aimed to show the impact of the metabolic syndrome (MeTS) on male sexual function based on VAI and the impact of increased levels of the VAI was investigated in patients with ED among the patients with and without MeTS. Methods:Participants who met MeTS criteria (Group 1, n=96) and without MeTS (Group 2, n=189) were included in this cross-sectional study. The MeTS diagnosis was made in the presence of at least three of the following criteria: serum glucose level higher than 100 mg/dl, HDL cholesterol level below 40 mg/dl, triglyceride level greater than 150 mg/dl, waist circumference greater than 102 cm and blood pressure greater than 130/85 mmHg. Demographic data were recorded; biochemical and hormonal tests were measured. Erectile and other sexual function scores were recorded. The VAI was calculated using the [(WC/39.68)+(1.88xMI)]xTG/1.03x1.31/HDL formula. Results:Mean age, smoking volume, T and T/E2 ratios of the groups were similar (p>0.05). Mean VAI was two-fold higher in patients in Group 1 (p<0.001) and erectile function score was lower in Group 1 than Group 2 (p=0.001). Other sexual function scores were similar (p>0.05). The METS was associated with an increased risk of ED (p=0.001). Logistic regression analysis showed that each integer increase of the VAI was associated with a 1.4-fold increased risk of ED (p<0.001). Higher T values were associated with a better erectile function (p=0.03). For the VAI=4.33, receiver-operating characteristic analysis showed a sensitivity of 89.6 % and specificity of 57.7 %. Conclusion:Compared to non-MeTS, the presence of MeTS has emerged as a risk factor for patients with ED with high VAI levels while the other sexual functions are preserved. Management of ED patients with MeTS should cover a comprehensive metabolic and endocrinological evaluation in addition to andrological work up.