IntroductionThe successful implementation of health information technologies requires investigating the factors affecting the acceptance and use of them. The aim of this study was to determine the most important factors affecting the adoption of health information technologies by doing a systematic review on the factors affecting the acceptance of health information technology.MethodsThis systematic review was conducted by searching the major databases, such as Google Scholar, Emerald, Science Direct, Web of Science, Pubmed, and Scopus. We used various keywords, such as adoption, use, acceptance of IT in medicine, hospitals, and IT theories in health services, and we also searched on the basis of several important technologies, such as Electronic Health Records (HER), Electronic Patient Records (EPR), Electronic Medical Records (EMR), Computerized Physician Order Entry (CPOE), Hospital Information System (HIS), Picture Archiving and Communication System (PACS), and others in the 2004–2014 period.ResultsThe technology acceptance model (TAM) is the most important model used to identify the factors influencing the adoption of information technologies in the health system; also, the unified theory of acceptance and use of technology (UTAUT) model has had a lot of applications in recent years in the health system. Ease of use, usefulness, social impact, facilitating conditions, attitudes and behavior of users are effective in the adoption of health information technologies.ConclusionBy considering various factors, including ease of use, usefulness, and social impact, the rate of the adoption of health information technology can be increased.