Objectives To examine whether the severity of lower urinary tract symptoms (LUTS), when controlled for other factors, is related to erectile dysfunction (ED) in the male veteran population. Early evidence suggests that LUTS may be associated with ED in men. Methods A total of 181 male veterans were prospectively entered into the study. They completed the Sexual Health Inventory for Men (SHIM) and International Prostate Symptom Score (IPSS) questionnaires. Of the 181 men, 144 also underwent uroflowmetry, including determination of the postvoid residual urine volume. Demographic and medical history data were recorded. Pearson correlation coefficients and multiple linear regression analysis were used to examine the relationship between LUTS and ED, as well as the effects of age and comorbidities. Results The correlation coefficient (r) for the SHIM score with the total IPSS was -0.17 (P = 0.023); with the obstructive IPSS, it was -0.20 (P = 0.006); and with the irritative IPSS, -0.05 (P = 0.492). Age was the only other factor with a statistically significant correlation with the SHIM score (r = -0.23, P = 0.002). Multiple linear regression modeling showed obstructive IPSS (P = 0.001) and depression (P = 0.017) to be the only statistically significant predictors of the SHIM score. A consistent negative correlation was found between obstructive IPSS and the SHIM score across age groups, with the strongest effect for men aged 60 to 70 years (r = -0.412, P = 0.003). Conclusions Obstructive LUTS correlated with, and were predictive of, ED, even after controlling for age and comorbidities. Although age correlated with ED, it did not add to the power of the multiple linear regression model composed of obstructive IPSS and depression.