Objective: To determine the relationship between erectile dysfunction and metabolic syndrome (MetS) in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Material and methods: Seventy-eight patients who were admitted to our outpatient clinic because of BPHrelated LUTS over 40 years of age were included in the study. Patients with LUTS and erectile dysfunction (ED) were evaluated by International Prostate Symptom Score (IPSS) and International Index of Erectile Function-5 (IIEF-5) forms. The National Cholesterol Education Program Adult Treatment Panel III criteria was used for the diagnosis of MetS. LUTS were classified as mild, moderate, and severe according to IPSS and ED was classified as mild- moderate, moderate, and severe according to the IIEF-5. For the evaluation of data, descriptive statistical methods (mean, standard deviation, median, frequency, ratio, minimum, and maximum) and also for the comparison of the variables with non-normal distribution in 3 or more than 3 groups Student’s t test, Mann-Whitney U, ANOVA, chi-square, Fisher Exact tests, and Pearson correlation analysis were used. P<0.05 was accepted as the level of statistical significance. Results: Mean age of the patients included in the study was 61.83±9.15. In 34.6% of the patients with MetS, 70.5% of the patients with ED and 37.2% of the patients with severe LUTS were determined. There were no significant differences between the mean age of patients with and without metabolic syndrome (p>0.05). There was a positive correlation with age and severity of LUTS but this relationship was not found to be statistically significant (p>0.05). Mean age of the patients with ED was significantly higher than those without (p<0.001). A statistically significant relationship was not observed between the mean IPSS scores and the severity of LUTS with Mets. However, we observed a weakly positive correlation between triglyceride levels and IPSS. Mean IIEF-5 scores of the patients with MetS were significantly lower than those of the patients without MetS. Severity of ED in the patients with MetS was significantly higher than patients without MetS. The percentage of ED in patients with severe LUTS was found to be statistically higher than other patients with mild, and moderate LUTS. In addition, we found a low degree of negative correlation between IPSS and IIEF-5 scores. Conclusion: In patients with LUTS as a consequence of BPH, when severity of symptoms increases, frequency of MetS increases proportionally and severe ED is observed much more frequently.