Purpose This study aims to examine hospital image, perceived medical quality, relationship marketing and word-of-mouth as the determinants of patients’ intent to revisit private hospitals in Penang, based on the theory of planned behaviour. Design/methodology/approach A quantitative study comprising a self-administered questionnaire was distributed to domestic and international patients at the airport, private hospitals and hotels located in Penang. The partial least squares structural equation modelling (PLS-SEM) approach was used to analyse and test the research hypotheses. Findings The results show that cognitive components (i.e. hospital image and perceived medical quality) do not have any significant influence on patients’ intent to revisit, while affective components (i.e. relationship marketing) and behavioural components (i.e. word-of-mouth) are important in increasing patients’ intent to revisit private hospitals in Penang, Malaysia. Trust has no significant mediating effect between predictor variables and patients’ intent to revisit, but it has significant association with affective and behavioural components. Practical implications The findings provide insights to medical marketing teams in promoting and increasing patients’ intent to revisit their respective hospitals and for the governments to sustain and enhance medical tourism in their countries. Originality/value This study is one of the few studies that looks at the relationship between hospital image, perceived medical quality, relationship marketing, word-of-mouth and patients’ intent to revisit private hospitals in Penang, Malaysia. This study also explored the direct and indirect effects of trust on patients’ intent to revisit that was still limited.