The coronavirus disease case, commonly known as Covid-19, has spread internationally since March 2020. Approximately 100 countries, including Vietnam, closed their schools due to a public health emergency, according to UNESCO. Due to the circumstance, teachers were forced to convert from in-person instruction to online instruction. In the context of Covid-19, this study investigated how EFL high school instructors felt about online English language education. A descriptive design and a mixed-methods approach were utilized in this investigation. Six EFL high school teachers in the Mekong Delta were interviewed for this study to get their perspectives. The findings demonstrated that the participants' opinions on the usefulness and simplicity of online instruction during the Covid-19 epidemic were overwhelmingly positive. Despite the challenges they encountered when conducting their online classes, the teachers were able to show the proper attitude toward using technology to teach. The pedagogical implications of online teaching and learning are also meant to encourage the development of innovative teaching strategies in the setting of high schools in the Vietnamese Mekong Delta