Although religion is an important cultural force that shapes consumers' values and norms, the taboo stigma attached to the investigation of religion's influences in marketing areas has limited the knowledge about how religion influences consumers' decision-making. This study explored the affect of Muslim motivation in following Islam in their decision-making process to perform behaviors that are subject to Islamic rulings known as fatwa. Three behaviors that are subject to fatwa declarations; smoking, listening to popular music and buying a Coca Cola soft drink, were chosen. Utilizing the Theory of Planned Behaviors, this study examined: 1) If a Muslim's motivation in following Islam is an effect in their cognitive and behavioral responses regarding the fatwa prohibited behaviors. 2) If Muslim motivation in following Islam is an effect in their decision-making in deciding to whether to perform fatwa prohibited behaviors. Based on a Malaysian university student sample, multiple analyses of variance with covariate's (MANCOVA) results show that a Muslim's motivation in following Islam, his or her gender and their interaction have significant effects in their responses in regards to the behaviors. Muslim males, who are extrinsically motivated towards Islam tended to report a greater intention to smoke, buy a Coca Cola soft drink and tended to report they experienced more social pressure to smoke as compared to others. Nonetheless, SEM analysis found that the sample's responses on items related to the Theory of Planned Behavior (TPB) about buying a Coca Cola soft drink brand did not fit the model. Other unaccounted for factors that may be related to the Muslims' decision-making about the product, such as possible consumer animosity, was not captured in the survey. The sample’s responses on smoking and listening to popular music provided a good fit to the model proposed. ii This study found that the Muslim respondents' motivation in following Islam had an effect on the role of perceived social pressure in their planning to smoke, and on the role of perceived social pressure in their planning to listen to popular music. Respondents' motivation in following Islam also had an effect on the role of perception of control in their reported smoking and listening to popular music. The intrinsically motivated Muslim consumers tended to be more concerned about others approval in their deciding to smoke and to listen to popular music, than the average extrinsic respondents. The intrinsic Muslim respondents also tended to perceive having incomplete control over smoking and listening to popular music, compared to their extrinsic counterparts. Respondents' attitudes towards smoking and listening to popular music were found to be not relevant in respondents' decision-making to perform the behaviors. This study also found evidence for the effect of type of fatwa prohibition ruling in Muslim respondents' responses and decision-making to perform behaviors in this study. Findings from this study suggest a significant effect of fatwa rulings on products or behaviors, among the sample of young Malaysian Muslim respondents. The findings highlight the needs for marketers to understand nature of fatwa rulings on products, in order to win over Muslim consumers in the marketplace.