On the implementation level of the National Foreign Language Project for the period 2008 – 2020, now extended to 2025 in Vietnam, Level 3/6 – VNFLPF (B1- CEFR) has been set as the learning outcomes for high school language learners. The English curriculum for Vietnamese upper secondary schools was promulgated, and guiding documents were launched, officially supporting EFL teachers in teaching and assessing language learners effectively to achieve the required learning outcomes. This paper reports the findings from an investigation into high school EFL teachers’ practices of assessing language learners in a city in Central Vietnam using interviews and assessment samples. From the findings, practical suggestions are made with the hope of providing a valuable basis for both learning improvement and teaching development.