Abstract  Background: Considering the vital role of telemedicine in dealing with the epidemic of COVID-19 and other diseases, this study was conducted with the aim of investigating the level of knowledge, attitude and practice of patients referring to the COVID-19 emergency department regarding the provision of medical services through telemedicine.   Methods: This study was conducted in the infectious diseases emergency department of Masih Daneshvari Hospital. A questionnaire regarding knowledge, attitude and practice of patients with COVID-19 about telemedicine was designed and completed by patients. The questions included demographic information, knowledge of patients, attitude, experience and satisfaction of patients in connection with the use of telemedicine in the control of corona disease. Finally, statistical analysis was performed using the non-parametric Kruskalwallis and Mann-Whitney tests.  Results: Out of the total of 200 participants in the study, 60% were men, 27% belonged to the age group of 40 years and below, 35% had university education and 26% were single. Also, 83% of the people in the study had access to a smartphone and 83.5% had access to the Internet. Based on the results obtained from the present study, the use of telemedicine is directly dependent on the knowledge, attitude and practice of patients, and younger people, with university education and unmarried people were more inclined to use telemedicine services. Also the attitude of women was more positive than men regarding telemedicine use. Patients had a positive attitude towards using mobile applications to receive information, record symptoms, and gain information about Corona.  Conclusion: Although the people present in the study had significant knowledge and attitude towards this issue, they did not have a proper performance regarding the use of telemedicine services and preferred face-to-face referrals to virtual ones. To solve this problem, it is recommended to consider appropriate training for both physicians and patients to improve their familiarity with telemedicine services and increase their confidence in using it. Most importantly, the role of physicians as a key element in improving the performance level of patients should be strengthened; so that by educating patients and encouraging them to use this new technology optimally, an effective step can be taken in advancing the goals of its use.