Background: Attrition of health professionals from public health sectors is found to be a barrier to effectiveness of health systems and to provide essential health service to population. In Ethiopia, the public health system is the major provider of health care service to the people. In particular, the poor segment of community uses public hospital, health centers and clinic, since the private health facilities are inaccessible and unaffordable to them. The aim of this study was to determine the magnitude and factors associated with health professionals’ attrition from public health sectors in Bahir Dar city. Methods: A Facility based cross-sectional study was conducted in September-October 2012. All inclusive sampling techniques of five years document reviews were used to select 727 health professional documents. Quantitative and qualitative data were collected using structured questionnaires and indepth-interview guides respectively, by trained data collectors. Descriptive statistics (frequencies, proportion and chi square test) were used to describe the study population in relation to relevant variables. To identify independent predictors of attrition, only variables that were statistically significant during bivariate analysis were entered into multiple logistic regression models to control the effects of confounders. Pvalues <0.05 were considered as statically significant. Result: The attrition rates of health professionals from public health sectors in Bahir Dar city were found to be 39.6%. Age, sex, marital status, educational status, workplace, current salary, professional category and work experience were the main factors associated with health professionals’ attrition from public health sectors. Conclusion: The findings showed that the level of health professionals’ attrition is high in the study area. Policy makers and health mangers should design appropriate retention strategies for health professionals at public health sectors in terms of most associated factors with attritions of health professionals to reduce the prevalence of health professionals’ attrition from public health sectors in collaboration with development partners and concerned body.