Background: The smoking of tobacco, by the use of cigarettes and water pipe, among children and adolescents has reached epidemic levels in the Middle East. There is evidence of a relationship between religiosity and tobacco use, namely that Muslim youth with higher religiosity engagement are less likely to smoke tobacco, which is in line with some of the Islamic doctrine on tobacco use. However, previous research has only focused on the number of days of religious engagement and has not examined the multiple factors of religiosity. The purpose of this study was to examine the relationship between religiosity and tobacco use among Muslim primary school students in Irbid, Jordan. Methods: A pilot repeated cross-sectional study was conducted in 2015 among Muslim school children enrolled in the 5th and 6th grades in the Irbid Governorate in the north of Jordan and followed up one year later. This thesis has developed a multidimensional measure of religiosity for Muslim youth in Jordan adapted from one developed for Muslim adults (El-Menouar, 2014) itself based on the Glock (1962) model of religiosity. This tool was utilised in the repeated cross-sectional study of Muslim youth in Irbid, Jordan. Multivariable logistic regression analyses were performed to measure the association between religiosity and tobacco smoking, both in 2015 only and pooling data from 2015 and 2016. Results: Nine hundred and twenty-six youth enrolled at baseline. The rates of ever-smoked for cigarettes and water pipes in 2015 were 15% and 36% respectively. This research developed statistical models of tobacco use to examine recognised demographic, family and peer influences, and family attitudes on tobacco use. The models then included of religiosity factors to examine their impact on the smoking outcomes. A four-factor model of Muslim children’s religiosity was developed comprised of Experience & Orthopraxis; Knowledge; Belief; and Devotion & Practice. Statistical analysis indicates that the scales are reliable and internally valid. The religiosity factor of Devotion and Practice demonstrated a protective effect, as did perceptions of the ruling on smoking in Islam. In addition, there was evidence that different factors, sex and parental attitudes in particular, related to cigarette and water pipe use within this population. Conclusions: This is the first repeated cross-sectional study to examine the association between religiosity and prevalence of smoking cigarettes and/or WP among adolescents using a modified multidimensional religiosity scale for Muslim primary school children in Islamic societies. The results indicate that religion can be a protective factor in child smoking behaviour. Religiosity therefore can be used at this stage as an anchor to guide behaviour. In summary, this research has demonstrated that religiosity can be an important anchor for this population to develop programs to assist in guiding tobacco use behaviour.