This article reviews the impact of the COVID-19 pandemic on key elements of transnational higher education (TNHE) in science, technology, engineering, and mathematics (STEM) disciplines. The challenges faced by mentors and mentees across the pre-, mid-, and post-pandemic periods in relation to teaching methods, learning outcomes, assessments, and academic integrity were examined. It was found that despite several issues and obstacles in the mid-pandemic era, TNHE programs continued successfully due to technological advancements and ongoing collaboration between host and home institutions. Teaching methods and assessment criteria were adapted with the help of digital tools, though academic integrity remained a consistent concern across the pre-, mid-, post-pandemic eras. Additionally, the article discusses the challenges faced by both host and home institutions in maintaining quality control and supporting professional development during the mid-pandemic period.