Background: There is increasing interest in low-and middle-income countries (LMICs) to introduce and scale-up digital health tools like electronic immunization registries (eIR), and electronic logistics management information systems (eLMIS) to support immunization services. An evaluation of the use of these tools was conducted in four LMICs to inform decisions about their further expansion and investments. Methods: Purposive sampling of regions, districts, and health facilities was done in each country based on predefined criteria. Primary data were collected between October 2021 and September 2022 in 50 health facilities in Guinea, 88 in Honduras, 36 in Rwanda, and 101 in Tanzania using semi-structured questionnaires, standardized competency assessments and data accuracy checks. Data focused on electronic tool usage, user experience, infrastructure, workforce needs, and decision-making, as well as immunization data quality and perceptions of health workers and vaccine recipients. Data analysis combined both quantitative and qualitative methods. Findings: The implementation of eIR and eLMIS was associated with improvements in National Immunization Programme (NIP) processes and outcomes. Users were satisfied with the tools (87 % satisfaction rate), and 95 % of users in the African countries valued the accessibility of information, with 91 % finding it accurate and complete. Some caregivers reported better organization and shorter waiting times in health facilities using the tools. Most eIR users noted improvements in process efficiencies (81 %) and immunization service delivery (89 %). In Rwanda and Tanzania data accuracy was higher in exclusively paper or electronic settings (60 %) compared to dual paper-electronic systems (45 %). eLMIS use was associated with improvements in vaccine stock data quality and reduced stock-outs. While 77 % of health workers were digitally literate, inadequate digital infrastructure was a key barrier to tool use. Interoperability with the Civil Registration and Vital Statistics system (CRVS) was limited, hindering the tracking of unimmunized children. Conclusions: To fully realize the potential of electronic tools in LMICs, full government ownership, targeted infrastructure investments, migration to fully electronic systems, and the integration of eIR with the CRVS will be essential.