We presented here our study on Vietnamese teachers and pre-service teachers’ view of nature of science (NOS) and some practical training activities that we used to develop their understanding of NOS. Results were taken from our workshop about nature of science (NOS) and science – technology – society (STS) approach at Can Tho University, Vietnam on 20 March 2013. Participants are around 30 Vietnamese lecturers and pre-service teachers of Can Tho university and 32 participants from Khon Kaen University. This workshop was funded by the project of KKU Science Education Mekong Technology Transfer that organized by science education program, Faculty of Education, Khon Kaen University. The purpose of the workshop was to introduce the recently focused education goal about the nature of science of science education worldwide and the STS approach to Vietnamese educators and teachers. This training workshop was conducted based on the constructivist lens where the prior knowledge and experience of the participants were employed to let them construct the concepts of nature of science by themselves through various activities. Reflections and discussion indicated that Vietnamese participants currently have some certain understanding as well as naïve conceptions about the nature of science. Most of the misconceptions were successfully transformed to the informed ones through the workshop except the idea of ‘the function of, and relationship between theory and law’. We also reported here the ineffectiveness of the VNOS-C of Lederman et al. (2002) in collecting Vietnamese conceptions about NOS. We discussed some possible reasons for this unsuccessfulness. Several suggestions for future researches on Vietnamese teachers’ understanding and thinking and for the next training workshops or training programs in Vietnam were made.