Telemedicine refers to a medical action where the patient and the physician are remote from each other, or where the two don’t meet face-to-face. It uses information and communication technologies as its medium. Recent developments of telemedicine are changing the public medical system. As a consequence, some problems are taking place, which need to be carefully discussed. For instance, telemedicine involves processing a wide range of medical information on the computer. At this time, some serious problems might happen. They include a wrong treatment of medical information that brings about the leakage of patients’ personal information or the infringement of their privacy. In telemedicine, additionally, patient-physician relationships are just formed online without face-to-face meeting despite trust and sympathy between he patient and the physician are quite important in medical treatment. So telemedicine needs trust and responsibility more than needed under traditional patient-physician relationships. Aristotle’s phronesis may be an important principle under which medical professionals practice telemedicine. Phronesis refers to knowledge required for good actions, that is, ‘practical wisdom’. The point of phronesis is that you should judge and decide how to behave given a current situation by using conventional knowledge, but considering the characteristics and individuality that situations may have. Medical professionals’ competence in telemedicine given lots of different patients and complications of the medical system may be dependent on how they can obtain the scientific knowledge of medical technology and use them to properly interpret the status and contexts of individual patients and how they can use their own insights to choose the best from alternative actions of treatment. Under the principle of phronesis, in other words, medical professionals should contemplate different actions specific for different situations before deciding the process of treatment that is best for individual patients in telemedicine.