Context: Although many countries have improved their vaccination coverage in recent years, the Democratic Republic of Congo (DRC) remains with unsatisfactory levels. Aims: The objective of this study is to document the relative importance of the factors that have in luenced the immunization coverage in DRC and to understand the extent to which cash support to the DRC by the Global Alliance for Vaccines and Immunisation (GAVI) addresses these issues. Materials and Methods: Data were collected using a modi ied Delphi and by the analysis of grants and annual progress reports submitted to GAVI. Results and Conclusions: The GAVI health systems strengthening (HSS) proposal is quite strategic. Therefore it should be complementary to other GAVI grants received by the DRC. This is not always so because the different GAVI windows [immunisation services strengthening (ISS), new and underused vaccines, HSS, and civil society support] do not overlap geographically and in the calendar. This is further aggravated by the narrow time horizon of all grants. Apparently, not enough thinking was done at the outset about how the GAVI HSS proposal was going to be implemented. Hence, the acknowledgement by the Delphi panelists that the major barrier to the effectuation of the GAVI HSS grants was in their implementation. The Delphi panel was silent about HR issues but the importance of these issues is captured in the 2006 GAVI HSS grant application. Signi icant delay in the implementation of the HSS proposal is associated with the lack of a reliable inancial management system. GAVI HSS has been catalytic in uniting key stakeholders in the health sector around the HSS strategy, including the DRC government itself.