Obstructive sleep apnea is considered a risk factor for erectile dysfunction. The aim of this study was to determine sleep architecture and assess daytime sleepiness in patients with erectile dysfunction. The study group included 280 patients. The 107 enrolled patients had reported erectile dysfunction. The control group consisted of 173 patients who had no history of erectile dysfunction. The Epworth sleepiness scale (ESS) was used to measure the subjects’ level of daytime sleepiness. All patients underwent a standardized overnight, single-night polysomnography in sleep laboratory. In the erectile dysfunction group, we observed increased ESS total score and N1 sleep phase duration. Mean and minimal oxygen saturation and mean oxygen desaturation were decreased in comparison to the control group. In summary, subjects with erectile dysfunction have altered sleep architecture, oxygen saturation parameters and increased daytime sleepiness.