The aim of this study was to investigate the relationship between penile color Doppler sonography (CDS) findings and sonographic endothelial parameters in patients with erectile dysfunction (ED), including intima-media thickness (IMT) of common carotid arteries (CCA) and flow-mediated dilatation (FMD) of brachial artery. Fifty-six ED patients were included in the study. Penile CDS, IMT of CCA and FMD of brachial artery were performed in all patients. According to penile CDS findings, 27 (48%) patients had non-vasculogenic and 29 (52%) patients had vasculogenic ED. Among 29 patients, 17 (30%) patients had cavernous veno-occlusive disease (CVOD) and 12 (22%) patients had arterial/combined insufficiency (AI). Median (interquartile range) FMD values of non-vasculogenic ED, CVOD and AI were 12.50 (6.54)%, 12.82 (7.41)% and 6.25 (7.17)%, respectively. FMD was found to be impaired significantly in AI group when compared to the other groups. FMD values of CVOD group were lower when compared to non-vasculogenic group, but the difference was not statistically significant. IMT values of vasculogenic ED patients were higher than non-vasculogenic ED patients (P<0.05). Although IMT values were higher in AI group when compared to CVOD, the difference was not statistically significant. The combined use of IMT and FMD established the diagnosis of vasculogenic ED with 100% sensitivity and 59.2% specificity. The positive predictive value was 72%, negative predictive value 100% and accuracy 80%. The combined use of brachial artery FMD and carotid arteries IMT measurements may be suggested as an alternative method to evaluate vasculogenic ED.