With the rapid development of technology for the past decades, online instruction has emerged as an alternative mode of teaching and learning and a substantial supplement to traditional teaching. At the Center for Foreign Languages, Can Tho University, online teaching has been growing recently, particularly due to many schools’ closures because of the Covid-19 pandemic. This small-scale study was conducted with a group of online teachers of English of the Center for Foreign Languages with the aim to understand the teachers’ challenges as well as their opportunities to develop online courses. The results revealed that the primary challenge of online teaching was about technology impacts on both teachers and learners. There were also suggestions for both administrators and teachers for enhancing quality of online teaching.