Extant research suggests that the pro-environmental consumer behavior (PECB) is beneficial for the environment as well as for businesses. Environmental benefits of the PECB include a reduced deterioration of the natural environment, an increased consumers’ well-being, an enhanced quality of life, and the achievement of a sustainable future (Felix and Braunsberger, 2016; Kalamas et al., 2014; Moser, 2015). The PECB brings benefits to businesses, such as, greater returns from higher demands for environmentally friendly products, an increased employee commitment, and an enhanced customer satisfaction (Menguc and Ozanne, 2005). PECB is a voluntary behavior of a consumer whereby the consumer deliberately seeks to minimize the harmful effect of his/her actions on the natural and man-made world, such as, purchasing products that are ecologically friendly (Steg and Vlek, 2009). Because of PECB’s important benefits, a considerable number of studies have explored the potential antecedents of PECB, such as, environmental value, knowledge, concern, and attitude, which are known as intra-personal/psychic variables (Ertz et al., 2016; Han, 2015). However, studies report that cultural values strongly interact with pro-environmental intra-personal factors in influencing the PECB (Belk, 1975; Soyez, 2012). Yet scholars are not comfortable to investigate the influence of religiosity, a specific cultural value, on the antecedents-PECB relationships (Felix and Braunsberger, 2016; Lindridge, 2005). This is unfortunate because religiosity is a dominant cultural value in many societies and it can influence different intra-personal factors and in-turn the PECB (Izberk-Bilgin, 2012). Defined as a belief that there is God and there are guiding principles set by God for people’s behaviors and deeds in this life (McDaniel and Burnett, 1990) religiosity is believed to be an important source of morality, ethics and environmental ethics (Rice, 2006; Vitell, 2009). Recently, Felix and Braunsberger (2016) found that religiosity moderates the environmental attitude-PECB relationship in a pre-dominantly Catholic context. Several other scholars have explored the impact of religiosity on the environmentalism in Judeo-Christian contexts (e.g., Izberk-Bilgin, 2012). However, no study has yet examined the impacts of the interactions of religiosity with other environmental intra-personal factors (i.e., value, knowledge, concern and attitude) on the PECB, neither has any study explored the preceding in a predominantly Islamic context. To fill this void, this research examines the moderating role of religiosity on the influences of four environmental intra-personal factors on the PECB in Oman, an Islamic country. This study will be helpful for various environmental stakeholders in promoting the PECB by leveraging ecological values inherent in religions through educational and promotional messages.