The Covid-19 pandemic had a profound effect on the delivery of teaching and learning. Recent studies indicate that Covid-19 interfered with years of educational gains and that university EFL instructors and students faced a variety of problems as they sought to adjust to pandemic requirements. This study explored Iranian university EFL instructors’ and students’ attitudes towards on-line education. It also examined learning and teaching barriers and challenges they encountered during Covid-19. 60 university EFL instructors and 93 students completed two on-line questionnaires. Following, six university instructors and six students took part in interview sessions. The results showed that students favored various advantages that on-line education offered such as convenience, comfort, accessibility, flexibility, and suitability. Students further appreciated the potential of new technology and the opportunities that on-line education brought. However, they identified poor Internet access and excessive screen time as common barriers that could hinder the success and sustainability of high-quality on-line education. The results, moreover, demonstrated university EFL instructors recognized the multiple challenges associated with on-line education. They expressed difficulties in tracking attendance during on-line classes, monitoring students’ progress in on-line classes, as well as concerns about security issues and privacy regarding on-line classes. We believe that the experiences of both university instructors and students should be considered when designing new approaches to empower them.