BackgroundOnline health communities (OHCs) provide platforms for patients to seek advice from physicians and receive professional suggestions online. It can improve the efficiency of patients’ diagnosis of simple diseases and alleviate hospital congestion. However, few empirical studies have comprehensively explored the factors influencing patients’ intention to use OHCs through objective data. This study aims to fill this gap by identifying key factors that influence patients’ acceptance of OHCs and proposing effective ways to promote the applications of OHCs in China.MethodsBased on the Unified Theory of Acceptance and Usage of Technology (UTAUT), extended with additional constructs identified with patients’ information demands in OHCs, this study developed a research model and proposed nine hypotheses. An online survey involving 783 valid responses was conducted in China to collect data to validate the proposed model. Confirmatory factor analysis and partial least squares (PLS) path model were conducted for instrument validation and hypothesis testing.ResultsPrice value, eHealth literacy, and performance expectancy are the most prominent constructs in the study context. Interestingly, relation quality was also found to have a significant positive relationship with behavioral intention.ConclusionsBased on these findings, OHC operators need to create a user-friendly platform, improve information quality, set reasonable prices, and establish consummate security systems. Physicians and related organizations can raise awareness and assist patients in developing the skills to appropriately comprehend and utilize information in OHCs. This study contributes to both technology adoption theory and practice.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12913-023-09469-6.