Introduction: Cesarean section is one of the operating delivery interventions. It is life-saving procedure. Currently the rate of cesarean section is increased above recommendation level both in developed and developing countries including Ethiopia. Objective: The aim of this study was to assess proportion of cesarean section delivery and its associated factors among mothers who delivered in health institutions in Bahir Dar city, North West Ethiopia 2019. Methods: Institution based cross-sectional study was conducted on 742 mothers from March 21 - May 21 2019. Data were collected through structured interviewer and review of medical notes with systematic random sampling technique. Data were coded, cleaned and entered by epi data version 3.1 then exported into SPSS version 23 for analysis. Binary logistic regression analysis was performed. At variables with p-value <0.2. Then enter to multivariable logistic regression analysis. Finally, variables with p-value <0.05 at 95%CI in multivariable analysis were the significant factors of cesarean section delivery. Crude odds ratio and adjusted odds ratio were calculated to show the strength of association between the dependent and independent variables. Results: The overall proportion of cesarean section delivery was 41.9% (95%CI :38%, 46%). Maternal request [AOR= 2.61; 95%CI:1.24, 5.51], secondary level of educational [AOR=3.04,95%CI:1.80,5.12] higher level of educational [AOR=2.04;95%CI:1.16, 3.59] , four and above ANC visits [AOR =1.60; 95%CI :1.08, 2.37], delivered in private institution [AOR =4.11; 95%CI :1.99, 8.45], previous cesarean section [AOR =10.04;95%CI :5.77, 17.46] and favorable attitude [AOR =1.57; 95%CI :1.08, 2.28] were significantly associated with cesarean section delivery. Conclusion: This study relived that the proportion of cesarean section was high as compared with world health organization threshold. Maternal request, maternal educational status, number of ANC visit, history of previous cesarean section, place of delivery and attitude towards cesarean section were significantly associated with cesarean section. Therefore, emphasis on evidence based indications, enlighten mothers concerning to risks and benefits of C/S and encouraging mothers to have VBAC is highly advised. Key words: cesarean section, proportion, associated factors, Bahir Dar, Ethiopia