Purpose: Through the present study, the authors investigate whether online practicum in teaching, with fellow teacher-candidates acting as students, can be effective and whether the teacher-candidates actually developed skills useful for their future teachings, through this form of practicum, which is necessary when, out of necessity, like in the case of the COVID-19 pandemic, there is no other option for universities. Design/methodology/approach: The method selected was qualitative research through in-depth interviews, since the present research question and the research topic in general have not been examined in the past. The authors gathered 45 teacher-candidates' journals on this experience, and, then, they interviewed them through semi-structured interviews. Findings: The findings indicated that the teacher-candidates got acquainted with new technologies in education to a great extent. Moreover, they developed skills that will be proven useful for their future teachings, like adaptability, flexibility and handling of students' interaction in online settings. Originality/value: The present case study consists of a paradigm of international value, since it fills in a gap in literature on an online alternative of practicum in teaching in cases of crisis, like the COVID-19 pandemic. Valuable insights are gained for researchers, practitioners and policymakers and best-practices for online teaching practicum have derived for future use.