Background: Erectile dysfunction is a distressing condition that impacts negatively a man’s well-being. Health-related quality of life (HRQOL) is a useful indicator of overall health that has gained wide acceptance as the patient-centred approach to assessing overall health. Objectives: This survey assessed the prevalence and pattern of erectile dysfunctions and their association with health-related quality of life. Methods: We conducted a hospital-based cross-sectional study and interviewed 392 sexually active adult male patients with the aid of interviewer-administered structured and semi-structured questionnaires at the general outpatient clinic of the University of Ilorin Teaching Hospital. The HRQOL was assessed with the World Health Organization Quality of Life abridged version (WHOQOL-BREF), while ED was assessed with the International Index for Erectile Function 5 (IIEF-5). Result: A total of 235 (59.9%) had ED: of those, 67 (28.5%) had mild ED, 77 (32.8%) had mild to moderate ED, 57 (24.3%) had moderate ED, and 34 (14.4%) had severe ED. Respondents with ED had lower mean HRQOL scores across all domains, (psychological f=94.700 p=0.001, Physical f=68.582 p=0.001, environmental f=30.314 p=0.0001, social f=8.346 p=0.004). Conclusion: The prevalence of ED was high among the study population. Although ED negatively impacted all HRQOL domains, the psychological domain had the most profound impairment.