Background: Erectile dysfunction (ED) has a negative impact on ones’ relationships with poor quality of life as inevitable result. Men’s sexual health has been forgotten in most developing countries and therefore the burden of ED and associated risk factors are not known in these settings. This study aimed to determine the prevalence and factors associated with erectile dysfunction among adult men in Moshi municipality, northern Tanzania. Methodology: A community based cross-sectional study was conducted in July 2019. Multi stage sampling technique was used to enroll men aged 18 years and above infour wards of Moshi municipality. The 5-item version of the International Index of Erectile Function (IIEF-5) scale was used to assess erectile dysfunction. Multivariate logistic regression was done to get factors associated with ED. Results: The mean age of the 381 men was 39.6 (SD ±16.8) years. Theoverall prevalence of ED on this study was 29.7%. The severity of ED among study participants was 13.4 % (51), 9.7 % (37), 3.7 % (14), 2.9% (11) participants had mild, mild to moderate, moderate and severe erectile dysfunction respectively. Age, tobacco use, overweight, hypertension and diabetes all showed significance association with ED. However, in multivariate logistic analysis only age ≥40 years and hypertension remain statistically significant associated with ED [(OR 5.2, 95% CI 2.68-10.21, P<0.001), (OR 11.5, 95% CI 5.8-22.76, P<0.001) and (OR 2.5, 95% CI 1.06-5.86, P=0.035) ] respectively. Conclusion: About one in three men in Moshi municipal had ED. High prevalence of ED among hypertensive individuals suggest a need to establish ED screening program during their routine clinic for early detection and treatment. Furthermore, education should be given on lifestyle modification to prevent hypertension and diabetes in the community. The outcome will be improvement of patient’s quality of life. Key words: Erectile dysfunction, Diabetes mellitus, Hypertension, Physical activities, Prevalence, Predictors, Tanzania