ObjectivesThis study was performed to determine the knowledge, attitude, and practice (KAP) of health care workers (HCWs) towards radiation protection.MethodsIn this systematic review study, three international databases (Web of Science, PubMed, Scopus) were searched for related published articles in the English language from 1 January 2000 to 1 February 2020. The quality of the included studies was evaluated using the Hoy et al. tool.ResultsOut of the 1,848 studies examined, 41 studies that were performed on 11,050 HCWs were included in the final stage. The results indicated that in most studies, more than half (50%) of the participants had average knowledge. Furthermore, 60% of the participants had a positive attitude, but in most studies, they had average practice regarding radiation protection. The most important recommendation for improving KAP among the participants was incorporating radiation protection standards in the student curriculum.ConclusionConsidering the results of the study, further attention should be paid to proper education regarding radiation protection standards and improvement of HCW performance.