Determinants of consumer decisions in choosing Islamic financial products in Indonesia-Darmawanauthor-Riska PrasastiauthorPurpose – This study aims to examine the determinants of consumer decisions in choosing Islamic financial products in Indonesia by integrating Brand Image Theory, Consumer Trust Theory and Source Credibility Theory within the Theory of Planned Behavior (TPB) framework. Design/methodology/approach – A quantitative approach was employed using purposive sampling. Data were collected through an online questionnaire distributed to 400 users and potential users of Islamic financial products, with 311 valid responses retained for analysis. The model was tested using structural equation modelling–partial least squares. Findings – The results reveal that institutional image, consumer trust and endorsement effectiveness each exert a significant positive influence on consumer decision-making. Among these, consumer trust emerged as the strongest determinant. The findings emphasise that perceived Shariah compliance, institutional transparency, and the credibility of religiously aligned endorsers enhance consumers’ intention to adopt Islamic financial products. Practical implications – The study provides managerial insight for Islamic financial institutions to strengthen trust-based communication, ensure consistent Shariah compliance, and select credible endorsers who embody Islamic ethical values. Originality/value – This research contributes to the Islamic marketing literature by combining behavioural, ethical and communicative dimensions within an integrated TPB framework and by offering empirical evidence from the under-researched Indonesian context.Ekonomi Islam2026Emerald Publishing LimitedArticle