The Zambia Immunisation Technical Advisory Group (ZITAG) was established in 2016 as an advisory body to provide evidence-based recommendations on vaccine policy. As part of the Gave Full Country Evaluation, we evaluated the functionality and effectiveness of ZITAG and related EPI committees through an online stakeholder survey of Interagnecy Coordinating Committee (ICC), ZITAG and Extended programme on Immunisation Technical Working Group (EPI-TWG) members, document review and key informant interviews. The survey was sent out via SurveyMonkey between May and July 2020 to 69 members of ZITAG, ICC or the EPI TWG. A total of 52 individuals responded (75%). Eight key informant interviews were also carried out at the national and global level in September 2020 to elaborate further on some of the quantitative findings and for triangulation. Findingsrevealed that the EPI committees were reasonably functional and effective entities, each with its unique role, though some overlaps occurred. Functionality was shown by having a broad membership with wide expertise and long-serving members; sub-committees existed and meetings were occurring regularly. Leadership and coordination structures also existed and were largely felt to be working well. Funding challenges however persisted, in particular for ZITAG operations and functionality of its subcommittees. Effectiveness and value addition fo the committees to the EPI was illustrated through decision-making processes and evidence use as well as relatively good country ownership in terms of commitment, legitimacy, capacity and accountability. Full independence and ownership may however be compromised by funding challenges. Recent changes to ICC terms of reference and focus beyond immunisation side-lined the EPI and weakened the linkage between ICC and ZITAG with many ZITAG recommendations not having been followed through by ICC as the ultimate endorsing entity.