Abstract Introduction: Liver fibrosis (LF) is a crucial factor in predicting adverse liver outcomes including cirrhosis and hepatic decompensation in chronic hepatitis. In addition, liver fibrosis is important in determining whether, when, and how to initiate antiviral therapy. The degree of LF or cirrhosis is an independent factor to predict mortality in chronic hepatitis B patients. Due to the limitations associated with the current diagnostic test for LF histology, the aspartate aminotransferase-to-platelet ratio index (APRI), has been suggested to identify patients with HBV-related liver fibrosis.Objective: This study aimed at assessing the prevalence of liver fibrosis in hepatitis B using Aspartate Aminotransferase to Platelet Ratio index (APRI) score and its associated factors among patients attending Rukunyu Hospital, Kamwenge District, South Western Uganda.Materials and methods: We recruited a total of 163 respondents, after informed consent. Blood was collected from them and was used for AST and complete blood count from which a platelet count was obtained. APRI score was calculated using the formula: APRI = AST (U/L)/(upper limit of the normal range) ×100/platelet count (109 /L). An APRI score of 0.5 and above was considered as an indicator of liver fibrosis.Results: Out of 163 study respondents, 15(9.2%) had APRI score of > 0.5, which was indicative of liver fibrosis, with those in age bracket 40–59 years 8(53.3%), male 9(60.0%), not employed 10(66.7%), Christians 10(66.7%), having household monthly income of 50,000-200,000/= 10(66.7%), living with their spouse and children 14(93.3%), drinking alcohol 9(60.0%) and smoking 9(60.0%) being more affected. On bivariate analysis, age group 60–75 years (P = 0.008, OR: 0.109, 95%CI 0.06–0.742), drinking alcohol (P ≤ 0.001, OR: 6.155, 95%CI 2.029–18.67) and smoking (P ≤ 0.001, OR: 72.5, 95%CI 15.53-338.45) had statistically significant association with liver fibrosis. On multivariate logistic regression analysis, only smoking (P ≤ 0.001, OR: 55.563, 95CI 6.78-454.887) had statistically significant association with liver fibrosis.Conclusion: The prevalence of liver fibrosis was high (9.2%) and there is a need for early screening of liver fibrosis in Hepatitis B patients to prevent further damage.