Back ground: Anemia is a condition in which the number of red blood cells is insufficient to meet the body’s physiological needs. Even though the problem of anaemia during pregnancy has been given emphasis, very little attention has been paid to postpartum anaemia. Postpartum anaemia results depression, cognitive and motor development defect, fatigue, dizziness, lethargy and decreased milk production. Majority of maternal deaths occur within the postpartum period; anemia is credited for 20% of maternal deaths in the world. Objective: The aim of the study was to assess the magnitude and associated factors of post-partum anemia among mothers at Bahir Dar city public health facilities, North West Ethiopia, 2020. Methods: Institutional based cross-sectional study was conducted among 547 mothers at Bahir Dar city, public health facilities from February to March 2020. Participants were selected by systematic random sampling and interviewed about their socio-demographic, obstetric, morbidity and nutritional related factors. A finger-prick blood sample was collected to determine hemoglobin lev¬el using HemoSmart hemoglobin measuring meter. Data was entered using epi-data version 3.1 and exported to SPSS version 23 for analysis. Bi-variable analysis was employed to identify candidate variables, those variables having p value <0.2 were entered to multi-variable logistic regression model. Finally, variables having p value < 0.05 were considered as significant predictor variables for post-partum anemia. Result: The overall prevalence of postpartum aneima among mothers in Bahir Dar city public health facilities was 35.3% (95% CI: 31.4-39.7% CI). Inter-pregnancy interval (AOR= 7.54; 95% CI: 3.78-15.01), educational status (AOR: 4.18, 95% CI: 1.49-11.66), consumption of Iron folic acid in post-partum period (AOR= 3.50; 95% CI: 1.97 – 6.27), perceived excess blood loss (AOR=5.44; 95% CI: 2.40-12.32) and pregnancy anemia (AOR= 5.54; 95% CI: 2.32 – 13.19) were found to be significant predictors of postpartum anemia. Conclusion: The prevalence of anemia was high among post-partum mothers. More than one in three of the mothers who had checked hemoglobin level were anaemic. Iron folic acid supplementation during post-partum period should be strengthen to avert the burden of post-partum anemia.