Coronavirus disease 2019 (COVID-19) has a profound impact on our society, and health care professionals are challenged by the present outbreak. A recent study showed that a significant proportion of second-line workers and frontline workers experienced psychological distress. Although these findings suggest the possibility that rehabilitation therapists, especially those who work at the hospital, experience psychological distress, their mental health state has been largely dismissed and the number of an evidence-based practice is limited. Here, we discuss the importance of focusing on the mental health of therapists by introducing studies that focus on the mental health of health care workers during the COVID-19, SARS, and H1N1 influenza pandemics. We then noted the need to track the dynamic relationship between the mental health of therapists and the COVID-19 pandemic by employing longitudinal data collection with psychological measures that reliably and validly capture the mental health of therapists. This approach would be effective for preparation for future pandemics, as we have learned much from previous pandemics. We hope that our Tutorial Note will help readers who are interested in the mental health of rehabilitation therapists and encourage future studies.