Agriculture has been and continues to assume center stage in the economic policy of Ethiopia. Adoption of teff crop (Eragrostis tef (Zucc.) Trotter) yield-enhancing technical efficiency is key to improving agricultural production and productivity. The general objective of this study aims to investigate determinants that influence the technical efficiency of teff yield in the Kache Birra district, Kambata Zone. The primary data was collected among 378 teff growers in research locations during the 2020/21 season. Descriptive statistics and econometric methods were developed for the data analysis. The estimated average value of technical, allocative, and economic efficiencies was 71.52%, 67.23%, and 63.54% respectively, which shows the existence of inefficiency in teff yield in the district. The findings of OLS regression indicated that technical inefficiency was affected by age, sex, education status, landholding, livestock holding, credit, extension, off-farm activity, land ownership and fertilizer use. Teff yield technical efficiency was associated with a significantly higher teff crop yield and per capita annual income of teff cultivator. Concerned bodies should give important attention to teff yield technical efficiency which is the base for improving yield. The summary of this teff yield technical efficiency by policymakers and plan designers could bring better enhancement to the teff cultivator in the study area.