Background: Immunization is a global health success story, saving millions of lives every year. Aim: This study aims to assess mothers' perception regarding routine immunization for their children during the Covid-19 pandemic. Design: A descriptive exploratory research design was used in this study. Setting: The study was conducted at four settings of maternal and child health care centers in Obour, Qalioubiya Governorate. Sampling: The study included a sample of convenience (380) mothers accompanied with their children under 2 years old. Tools of Data Collection: Tool I: Structured interview questionnaire divided into five parts: Part I: It was concerned with demographic characteristics of the mothers and children. Part II: Presented health history of children, health needs and health problems. Part III: Displayed mothers' knowledge regarding routine immunization for their children during Covid-19. Part IV: Mentioned mothers' reported practices regarding routine immunization for their children. Part V: Revealed mothers' perception regarding routine immunization for their children. Tool II: It concerned with anthropometric measures for children. Result: The current study showed highly statistically significant differences between mothers' total knowledge and their reported practices as well as mothers' perception regarding routine immunization for their children during the Covid-19 pandemic. Conclusion: Findings of this study concluded that there was lack of mothers' knowledge toward routine immunization, which in turn affected their practices and their perception regarding routine immunization and MCH policy during the Covid-19 pandemic. As well, there were statistically significant relations in total score of knowledge and mothers' reported practices as well as mothers' perception regarding routine immunization for their children during the Covid-19 pandemic. Recommendation: Counseling session should be offered by community health nurses to upgrade parents' knowledge, practices and perception with special emphasis on less educated ones regarding immunization during the Covid-19 pandemic.