Through the UI-FHS project, JSI developed a Microsoft Excel-based Immunization Data Triangulation Tool (IDTT) with five regional health bureaus in Ethiopia. The tool triangulates immunization service statistics from DHIS2 with supply chain data from mBrana logistics management information system to produce ratios that can reveal data quality issues, such as over-reporting, or programmatic issues, such as consistent understocking of vaccine and supplies. In addition to describing how IDTT was developed and used, this article discusses the findings from key informant interviews that aimed to understand the feasibility, benefits, and challenges of using IDTT, as well as the data triangulation process.