PurposeThe religious-based brands are increasing daily, and different organizations target religious consumers. However, a scarcity of research in developing nations makes it difficult to determine how customers evaluate religious brands. This study aims to develop a model based on Ajzen’s (1985) theory of planned behaviour (TPB). It incorporates the three mediating factors of religious brand attitude, subjective norms and perceived behavioural control.Design/methodology/approachA total of 499 (232 Malay and 267 Thai Muslim) respondents were surveyed systematically by adopting the purposive non-probability sampling technique. Empirically three studies with the extended model were tested in a cross-cultural context.FindingsThe results illustrate that the religious brand attitude affects the buying behavioural intentions of Muslims. The analysis found the significant role of Islamic brand attitude and mediating variables. Islamic brand by the customer is the second most significant component after Islamic brand by country of origin. The research provides a theoretical model for the research foundation and a model to analyse religious brands in diverse backgrounds.Research limitations/implicationsOnly three different religious brand views were considered independent factors in this study, together with the development of TPB behavioural expectations. The research looked at three different regions in Malaysia as well as Thailand. The research also provides a model that can be used to analyse how various customers view well-known companies and religious brands.Practical implicationsResearchers, teachers and practitioners in the domains of advertising, marketing communications, consumer behaviour and sociology will find this study useful.Originality/valueThe authors develop a novel dual religiosity conceptual model to delineate the sequential nature of religious opinion formation, behaviour and consumption of religious brands. In addition, the authors provide an example using the PLS model analysis as a supporting example.