Background: Exclusive breastfeeding means infants were fed only breast milk, not even water, one day (24 hrs.) before the survey was conducted. It is considered as core practice to achieve almost all 2030 Sustainable Development Goals, specifically sustainable development goal 2 which focuses in ending hunger and improving nutrition and goal 3 which focuses in reducing child and maternal mortality. The objective of this study was to assess the prevalence of exclusive breastfeeding practice and its associated factor among first time mothers in Bahir Dar city, North West Ethiopia.Method: A community based quantitative cross sectional study was carried out from March to April, 2016 among 423 first time mothers in Bahir Dar city. Study participants were selected by busing simple random sampling method i.e., lottery method. Data on infant feeding practice were collected by trained interviewers who used a structured questionnaire. Both binary and multivariable logistic regression were used to determine factors associated with exclusive breastfeeding. Statistical significance was declared at P -value <0.05.Results: Prevalence of exclusive breastfeeding practice 24 hours before the survey was 57.3 %( 95%CL: 52.3%, 62%). Mothers not being married (AOR 2.787,95 %CI: 1.083, 7.171), were supported by their husband (AOR 3.658, 95%CI: 2.132, 6.278), with no breast complication (AOR 3.658, 95% CI: 2.132, 6.278), who had four or more antenatal care follow up (AOR 2.512, 95%CI: 1.494, 4.233) were more likely to practice exclusive breastfeeding. On the other hand, mothers who were living in nuclear family (AOR 0.48, 95%CI: 0.231, 1.001) were less likely to practice exclusive breastfeeding. Conclusion: The prevalence of exclusive breastfeeding practice in the study area was lower than the national recommended level. In this study maternal age, number of antenatal care visits, husband support, breast complication and type of family were predictors of exclusive breastfeeding. Involving partners during infant feeding counseling and education, creating awareness about breastfeeding, special attention for the first time mothers, and prenatal education for expectant parents were recommended to improve exclusive breastfeeding among first time mothers.