ObjectivesThis study aimed to evaluate the knowledge, attitude, practice, and clinical recommendations of health care workers (HCWs) towards COVID-19.MethodsIn this systematic review study, international databases (Web of Science, PubMed, and Scopus) were searched for the relevant studies published in English from the inception of databases until July 30, 2020. Hoy et al.’s tool was used to evaluate the quality of studies. All search steps, screening, selection of studies, quality assessment, and data extraction were performed separately by two researchers.ResultsOut of 3460 articles searched, 28 articles conducted on 16,427 HCWs were included in the study. Most of the HCWs had good knowledge (72.2%), a positive attitude (70.9%), and good practice (78.8%) towards COVID-19. The most important clinical recommendation to improve knowledge, attitude, and practice (KAP) was to provide HCWs with a periodic training program regarding COVID-19. The most important source of information for HCWs on COVID-19 was social networks.ConclusionsDespite HCWs’ good knowledge, attitude, and practice (KAP), it is recommended to periodically review KAP and carry out further studies in different countries as well. It is also recommended to use social media to improve KAP.