Although classroom assessment is well documented to cultivate learning and assist learners in achieving their goals and objectives, little is known about online classroom assessment practices in Asian EFL contexts. This study explored Vietnamese EFL teachers' synchronous online classroom assessment practices from a face-saving perspective. Its aims were twofold: (1) to explore how Vietnamese EFL teachers assess students regarding the face-saving culture and (2) investigate students' beliefs about the teachers' assessment practices. Data were collected from 18 recordings of online classes, semi-structured interviews with six teachers and twenty students, and a questionnaire administered to 224 students. The results show that the students generally preferred private and anonymous feedback, as their weaknesses were not disclosed to their classmates. To protect the students' face, the teachers divided students into small groups to conduct assessment and give feedback or they privately provided feedback to individual students. This does not mean Vietnamese students were likely to reject feedback, but they wanted to avoid causing conflicts among classmates. The results suggest contextualizing classroom assessment to suit the learning culture of Vietnam.