Objective:Some epidemic diseases such as coronavirus disease 2019 (COVID-19) have caused many physical,psychological,and social challenges,despite the existence of treatment strategies.Many people are looking for complementary and alternative medicine (CAM) to prevent such diseases.The present study was performed to determine how some types of CAM were being used during the COVID-19 epi-demic in Iran.Methods:The present study had a cross-sectional descriptive correlational design.All Iranian residents above 17 years old were eligible to participate in the study.A total of 782 participants completed a demo-graphic information questionnaire,a questionnaire about their use of CAMs and a questionnaire about their satisfaction with the CAMs they used.Web-based sampling was conducted from 20 April 2020 to 20 August 2020.Results:Of the participants,84％ used at least one type of CAM during the COVID-19 outbreak.The most used CAMs were dietary supplements (61.3％),prayer (57.9％),and herbal medicines (48.8％).The majority of the participants (50％-66％) have used CAMs to prevent the transmission of COVID-19 or to reduce anx-iety caused by the COVID-19 pandemic.CAM use was associated with sex,having children,place of res-idence,COVID-19 status,and source of gathering information about CAM (P ＜ 0.05).All 32 participants who had been infected with COVID-19 used at least one type of CAM for treatment or alleviation of the disease symptoms.Conclusion:During the COVID-19 outbreak,some types of CAM,particularly nutritional supplements,medicinal herbs,and prayer,were commonly used to prevent COVID-19 and reduce pandemic-related anxiety.