Background: Traditional Chinese medicine (TCM) and Western medicine are available and have a long history in Hong Kong. Little is known on the intention to use TCM in Hong Kong. In this study, the intention to use TCM were examined by the extended theory of planned behavior.Methods: An online cross-sectional survey was conducted from 15 and 29 November 2021. Respondents’ attitude towards using TCM, intention to use TCM, knowledge, perceived behavioral control, perceived service quality, satisfaction, subjective norms and demographic characteristics were collected from the survey. To examine the conceptual framework in this study, partial least square structural equation model (PLS-SEM) was adopted.Results: In total, 446 responses (completion rate = 74.3%) were analysed. Attitude towards TCM was the strongest predictor to the intention to use TCM followed by satisfaction and subjective norms. Attitude had a partial mediating effect on the relationship between subjective norms, perceived behavioral control and intention to use TCM. Attitude had a full mediating effect on the relationship between knowledge and intention to use TCM. Satisfaction had a full mediating effect on the relationship between perceived service quality and intention to use TCM.Conclusions: This is the first study to investigate the predictors of the intention to use TCM in Hong Kong by using TPB. Individuals’ attitude towards TCM has showed stronger effect to the intention to use TCM than other predictors, such as satisfaction, perceived behavioral control and subjective norms. To enhance the intention to use TCM in Hong Kong, key stakeholders, including TCM professional organisations, health professionals and policymakers, should develop a positive attitude towards TCM among Hong Kong population.