Constructivism was introduced to Vietnam through many ways such as workshops, books, the Internet, and so on. However, due to the lack of professional education, fundamental ideas of constructivist learning perhaps were missing or neglected through classroom activities. Furthermore, due to the influence of culture and society, Vietnamese constructivism certainly has its own agenda. This paper adapted the Constructivist Learning Environment Survey (CLES) which was originally developed by Taylor and Fraser (1991) to investigate the classroom environment in a Physics Teacher Education programme in Vietnam, as well as to illustrate Vietnamese teacher educators' views in employing constructivist learning. Fifteen teaching periods in seven different classrooms were observed, and five teacher educators from those classes were interviewed. Participants are lecturers and bachelor students of the Physics Teacher Education programme at Can Tho University, Mekong Delta region, south of Vietnam. Results showed that all five scales of the CLES in these classrooms are at the intermediate level. All the lecturers indicated positive attitudes about constructivism and have certain methods to perform these constructivist issues in their classes, but they have problems in practical instructional strategies for some scales. Therefore, we suggest that professional development programmes on how to apply constructivist theory, based on each particular scale of the CLES, are essential. This is especially true in scientific uncertainty, critical voice, and shared control. Yet, in a country that highly appreciates Confucianism with social order, not all aspects of an ideal constructivist learning environment should be equally improved. Generally, we believe that constructivist learning will be a key answer to the problem of the generally passive learning style in Vietnam.