Background: Acute bloody diarrhea (dysentery) is defined as an acute bout of diarrhea lasting less than 14 days in which subjects are passing grossly bloody stools. In Africa, an estimate of 115 people dies of diarrheal diseases every hour due to poor sanitation and hygiene. Acute bloody diarrhea is one among the 20 prioritized public health importance diseases. However, studies related to its determinants were not well known in the study area. Objective: To assess the determinants of acute bloody diarrhea among adults who visit outpatient departments in government health facilities Bahir Dar Zuria, North West Ethiopia, Methods: A facility-based Case-control study was employed between March 24 –May/19 /2019 among 326(81case, 245 control) adults’ age ≥18years who visited the outpatient departments in the public health facilities using systematic random sampling. Data were collected by trained nurses using interviewer-administered structured questionnaires, entered using Epidata-3.1 and exported to the SPSS version-20 for analysis. Various descriptive and analytical statistics were computed. Variables with p value ≤ 0.2 in bi-variable logistic regression analysis were taken into multivariable logistic regression analysis. Finally, Significances of variables was considered at p-value of <0.05 Result: A total of 321(81cases, 240 controls) were participated with a response rate of 98.5 %( 100%casesand 98%controls). water consumption per capital ≥ 20 Litters [AOR=0.32(0.17-0.63)], water lost from main source ≥one day [AOD=3.43(1.65-7.14], draw water by dipping [AOR=2.95(1.23-7.07)], use of shared latrine [AOR=8.48(3.49-20.57)], infrequent hand washing before food preparation[2.27(1.08-4.75), no detergent use during hand washing [AOR= 4.37;(2.01-9.48)] were among the determinants of acute bloody diarrhea. Conclusion and recommendation: Based on this study, water availability and consumption, not having independent latrine, knowledge about bloody diarrhea and personal behavior (no habit of hand washing before food preparation and no use of detergents) were statistically significant factors to bloody diarrhea among adults of the study area. It is vital to access water sources, improving latrine ownership and regular awareness creation about the cause, transmission, prevention and management of acute bloody. Key words: Bloody diarrhea, Adults, Determinant factors, Bahir Dar Zuria district, Ethiopia