Objective: This study aimed to determine the incidence of erectile dysfunction and its correlation with LUTS in adult Nigerian male patients presenting with LUTS to the Urologist. Background: LUTS either singly or in combination with ED, represents a considerable problem for the ageing men. This is due to the negative impact they have on the patients’ QoL. Determination of the incidence of ED and its relationship with LUTS is therefore important in proper care of these patients. Patients and Methods: One hundred and ten patients with LUTS were recruited from urological outpatient clinic of NAUTH. The sociodemographic data were collected while ED and LUTS were assessed with IPSS and IIEF questionnaires respectively. Findings were subjected to statistical analysis. Results: The mean age of patients was 65 ± 7.97years. LUTS were most prevalent within age group 71-75years. In 54.5%, the highest level of education was primary. The total incidence of ED was 63.6% ranging from mild to moderate ED with no severe ED recorded. The severity of ED showed strong positive correlation (P=0.0001) with severity of total LUTS score, while QoL showed a significant relationship (p<0.05 and p<0.01) between severity of voiding phase LUTS and severity of ED. Conclusion: The results from this study have shown that ED is prevalent in patients with LUTS. Its severity worsens with increasing severity of LUTS, with significant negative impact on QoL of patients especially the voiding phase LUTS.