This study aims to determine, from the perspective of investors, the factors that predict Islamic unit trust (IUT) investment intentions. Additionally, this paper examines the moderating effect of fintech self-efficacy (FSE) on the relationship between attitude and investment intention. A total of 392 data were collected from IUT investors in Malaysia and analyzed using partial least squares structural equation modeling. The findings reveal that subjective norms have the highest impact on investment intention, followed by attitude and FSE, while religiosity is not significantly associated with investment intention in Islamic unit trust funds. Attitude significantly mediates religiosity-intention and Islamic financial literacy-intention relationships. FSE significantly moderates the attitude-intention relationship. The results shed light on the key factors that increase investing behavior and have direct managerial implications with regard to marketing strategies and target markets. These findings suggest that IUT service providers should take the lead in attracting customers through effective and targeted marketing initiatives, particularly by enhancing customers’ FSE and capabilities. This study provides empirical evidence on the interrelationships between Islamic financial literacy, religiosity, and FSE in examining investors’ behavior using the Theory of Planned Behavior framework. The study explores the moderating role of FSE on the relationship between attitude and investment intention.