The present study investigates teachers‘ perceptions of the values of the CEFR, the perceived readiness and necessity of its application, and the work involved in its application process. Also, it explores teachers‘ responses to the use of the CEFR to renew the general English curriculum, reflected in how they changed their teaching activities, adapted the assigned textbooks and modified their assessment practice. The study was a case study applying the mixed method sequential explanatory model (Creswell & Clark, 2007). Data were collected from thirty-six GE teachers at a university in Vietnam by means of a forty-nine-item questionnaire. Eight semi-structured in-depth interviews were conducted.