Introduction: Quality management system is a set of coordinated activities to direct and control an organization in order to continually improve the effectiveness and efficiency of its performance. So, information about the status of health sector quality management system implementation is necessary. However, there is limited information about the quality management system implementation in the study area as well as at national level.Objective: the aim of this study is to assess quality management system implementation and its associated factors at governmental hospitals in Addis Ababa, Ethiopia. Methods: An institution-based cross-sectional study was conducted among 422 health care providers working in public hospitals in Addis Ababa. Simple random technique was used to select both the study settings and study participants. Data were collected by using structured written questionnaire after obtaining written consent from the respondents. The collected data were entered into Epi-data version 3.1 and analyzed using SPSS Version 25. Bivariate and multivariate analysis was done. Variables which had p-value <0.05 at 95%CI were considered as statistically significant association with dependent variable in multivariate analysis. Result was presented in text, table and figures. Result: A total of 422 study participants were participated in the study with the response rate 100%. The mean age of the study participants was 31.46 (SD=5.77) years. The majority (44.5%) of the study participants were below 30 years of age and 55.0% were female by sex. This study revealed that nearly 52% of quality management system were not implemented in the selected health facilities. Being 35 years and above (AOR =1.99) in age, ever heard about QMS (AOR 1.56) by the staff, and those staff knows the availability of QMS (AOR= 2.31) were among variables that identified as predictors of QMS implementation in the study area.Conclusion and recommendation; This study concluded that the level of QMS implementation in the current study area is suboptimal. Age of the study participants, previous hearing about QMS, and knows the availability of QMS were among variables that identified as predictors of QMS implementation in the study area. Therefore, health facilities are recommended to educate their staff about QMS implementation.