Background: Adverse birth outcomes are closely associated with increased fetal and neonatal mortality, morbidity, and impaired growth and cognitive development in both developing and developed countries. However, the effect of maternal nutritional anemia on birth outcome among anemic and non-anemic mothers is not well studied. Objective: To determine the effect of maternal nutritional anemia on the birth outcome among anemic and non-anemic mothers delivered in Marie stopes International Ethiopia Bahir Dar MCH center. Methods: Facility-based comparative cross-sectional study was employed by reviewing electronic health record data of 1320 mothers that delivered at Marie stopes International Ethiopia Bahir Dar MCH center from November 2016 to December 2019. Data was collected from randomly selected 440 anemic and 880 non-anemic mothers from February 20 to March 5, 2020. Descriptive statistics like frequency, percentage, mean and standard deviation was calculated. Logistic regression analysis was employed to identify factors associated with adverse birth outcomes. Those factors that had P-value <0.2 in bi variable analysis were entered into multivariable logistic regression analysis and investigate independent predictors by controlling for possible confounders; significance of statistical association was tested using 95% CI. Findings: In this study, 440 anemic and 880 non-anemic mothers who give birth were involved. The magnitude of adverse birth outcome among anemic mothers was higher than the non-anemic mothers (20.9%, 13.6%) respectively. Women with hemoglobin level less than 11 g/dl were found 1.5 times more likely to experience adverse birth outcomes when compared with those with Hgb level greater than 11 g/dl. Mothers who had labor duration > 24 hours were 2.405 times more likely to have adverse birth outcome than those who had labor duration <= 24 hours (AOR 2.405, 95% CI: 1.389, 4.163) and multi- parous mothers were 1.608 times more likely to have adverse birth outcome than primi-parous mothers. (AOR 1.608, 95% CI: 1.168, 2.213). Conclusions: The magnitude of adverse birth outcome is high and women with hemoglobin level less than 11 g/dl, multi-Parity and labor duration greater than 24 hours were significantly associated with adverse birth outcome for anemic and non- anemic groups. Therefore, early detection and treatment of anemia, health education on family planning and to manage long duration of labor is vital to reduce the effect of anemia on adverse birth outcome.