© 2020, The Author(s), under exclusive licence to Springer Nature Limited.The aims of this study were to examine the microvascular network of the retina using the optical coherence tomography angiography (OCT-A) device in patients with erectile dysfunction (ED) and to determine whether the OCT-A values could assist in the differential diagnosis of ED. The study design was prospective, observational, and cross-sectional. The vessel densities (VD) of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and retinal peripapillary capillary plexus (RPCP) were assessed using OCT-A in patients with ED and healthy subjects. All the participants were evaluated and scanned for systemic and hormonal disorders and those with ED also underwent penile Doppler ultrasonography (PDU). After recording the data, the participants were divided into three groups: organic ED, psychogenic ED, and healthy control. The relationships between the OCT-A parameters and other clinical findings were analyzed. The right eyes of 80 patients with ED and 40 healthy volunteers were evaluated in this study. Of the ED patients, 46 were included in the organic ED group according to the results of PDU. The VDs of DCP, SCP, and the temporal sector of RPCP were significantly lower in the organic ED group than the psychogenic ED and healthy control groups. The VDs of SCP and DCP were correlated with the peak systolic velocity of both left and right penile cavernous arteries. The VDs of DCP were also correlated with the left and right resistive indexes. In conclusion, the OCT-A data of SCP and especially DCP could be helpful in evaluating ED, and provide reliable information about the origin of the disease along with the other laboratory testing and penile vascular evaluation.