The importance of medical personnel’s mental health is emphasized in the COVID-19 era. The characteristics of traditional Korean medicine (KM) may affect the mental health of nursing staff working at KM clinics. In this case series, we report the first attempt to apply an online mindfulness program to the nursing staff in a KM clinic in Korea. For three female nursing assistants, an online mindfulness program consisting of five sessions was offered for two months. After the program, a decrease in emotional labor was observed in two participants, and a decrease in the level of burnout was observed in all participants. One participant showed an increase in their emotional labor level, which was associated with an increase in deep acting. The participants expressed a high level of satisfaction with this program in terms of recommendations for peers and willingness to participate again. As this report is a case series, larger studies are needed to fully evaluate the benefits of the program on emotional labor and burnout of KM clinic nursing staff. However, the potential benefits of emotional labor and burnout, high satisfaction, and some challenges identified in this case series can be considered in future extensions and modifications of the program.