Background: Erectile dysfunction can be defined as an inability to initiate and have a persistence erection firm enough to have satisfying sexual intercourse. There has been an increase prevalence of erectile dysfunction (ED) in the general population especially among diabetic patients. This seems to be a neglected problem in low income countries. Generally, little is known about erectile dysfunction and associated factors among diabetic patients in a study area and in a country at a large Objective: To assess prevalence and associated factors for erectile dysfunction among diabetic patients in Adare general and Hawassa Comprehensive Specialized Hospital, Hawassa, southern Ethiopia. Methods: Institution based cross-sectional study was conducted on 356 adult male diabetic patients randomly selected from Adare General and Hawassa Comprehensive Specialized hospitals. A simple random sampling technique was used to select the study units using list of patients from the registry. The number of patients to be selected from each hospital was proportionally assigned based on the total population of DM patients following chronic care during the study period. Data were collected by 2 data collectors and 1 supervisor. The data were entered into EPI-ENFO version 7 and then, exported to SPSS version 20 for analysis. Then, a descriptive statistics and multiple logistic regressions (bivariate and multivariate analysis) were carried out. Result: - The prevalence of erectile dysfunction was 72.2%. After adjusting for all factors, age [AOR=3.2, 95% CI, (1.32, 4.34)], duration of diabetes [AOR=17.7, 95%CI: (6.87, 48.01], drinking alcohol [AOR=3.23, 95% CI: (1.03, 10.44)] and poor glycemic control [(AOR=10.3, 95% CI, 3.92, 27.44)] Conclusion.The results of this study found the prevalence of erectile dysfunction 72.2%. Age, duration of diabetes, poor glycemic control and drinking alcohol was significantly associated with erectile dysfunction.