This research studied two topics: First, applying El-Menouar’s Muslim religiosity scale (2014) where in Indonesia it had never been used. Second, extending the Theory of Reasoned Action with the variable of religiosity. We took the sample randomly from 4 cities and 4 regencies in Indonesia. Data gathering by questionnaires, interviews, observations, and reviews of relevant literature. Structural Equation Modeling is an analytical tool for measuring variables and for hypotheses testing purposes. We employed Latent Variable Score to simplify religiosity construct. The results showed that attitude and subjective norms empirically prove to have a positive effect on intention to wear hijab. While religiosity has no effect on intention to wear hijab, it does, however, affect the attitude. The influence of subjective norms on intention to wear hijab is greater than the influence of religiosity on attitudinal-mediated hijab wearing intention. Because of the chosen research approach, the research results may lack generalizability. In the future, we suggest others to retest the conceptual model in order robust it. For business, marketing communications need to involve a fashionable Islamic public figure. The goal is to change consumer behavior through an influential person and change the underlying beliefs of attitudes to be positive to the product. The application of El-Menouars restricted Muslim religiosity scale is the first in Indonesia. This study also strengthens Theory of Reasoned Action as one of the prominent theories of behavior. Key Words: Religiosity, Attitude, Hijab-wearing Intention, Latent Variable Score, Theory of Reasoned Action, Muslim Religiosity Scale.