Abstract: Although the Government of Nepal has achieved high and sustained childhood vaccination coverage, reaching under-immunized and zero-dose children requires different. The purpose of this study was to identify critical success factors that contributed to exemplary growth in childhood routine immunization coverage in Nepal. Findings from this research may identify transferable lessons and support actionable recommendations to improve national immunization coverage in other settings [10]. Using human-centered design and rapid inquiry tools, such as the Behavioral and Social Drivers of Vaccination (BeSD) tool, the research identified the enablers and barriers to vaccination by interviewing the caregivers of fully immunized, under-immunized, and zero-dose children. Explore a curated collection of zero-dose immunization case studies highlighting approaches to identify and reach zero-dose and under-immunized children and missed communities. To compare immunization coverage and equity distribution of coverage between 2001 and 2014 in Nepal. We used data from the Demographic and Health Surveys carried out in 2001, 2006 and 2011 together with data from the 2014 Multiple Indicator Cluster Survey. Although the immunization program in Nepal has achieved the target of 90% crude coverage of all the childhood vaccines, the age-appropriate coverage is significantly low which undermines the effectiveness of the vaccines administered. This study evaluates the performance of Nepal's national immunization program by analyzing district-level vaccination coverage and dropout rates from 2009 to 2022 to identify trends and disparities across different routine vaccinations.