Immunization-related resources, such as toolkits and guidance, are designed to address critical technical components of immunization activities. Resource designers and implementers may benefit from additional information to identify strategies to support uptake and use of the resource—including implementation best practices. As a work plan activity in the 2023 project year, MOMENTUM Routine Immunization Transformation and Equity examined existing immunization-related toolkits and guidance to identify opportunities to improve uptake and use. As a foundational step to help the project prepare for these activities, the Measurement, Adaptive Learning and Knowledge Management Lab (MAKLab) for MOMENTUM conducted a desk review of relevant gray and published literature and conducted key informant interviews to identify known facilitators and barriers to the uptake and use of immunization-related resources. The analysis primarily focused on implementation of immunization-related resources, but non-immunization resources were considered if the type of resource, user, or use was similar to the immunization context. Findings from the desk review and interviews were synthesized into a list of factors associated with uptake and use of immunization-related toolkits and guidance.