The aim of the study was to investigate a perceived severity of religious intolerance, and reasons behind it, among different religious groups in Pakistan. A questionnaire measuring religious intolerance was completed by 199 university students (females M = 23.8 yrs, SD 5.3, and males M = 24.6 yrs, SD 5.6) from four religious groups: Sunni, Shia, Ahmadi, and Christian. Questions regarding the severity of intolerance were included as well as the following seven scales measuring possible causes for it: impact of the school curriculum, lack of knowledge about other groups, impact of hate literature, lack of social justice, family background and peer pressure, media impact, as well as external power influence and history. Respondents of all groups agreed upon the severe level of religious intolerance towards Ahmadis. Regarding the other religious groups, opinions differed. Sunni respondents rated the seven causes for religious intolerance as lower than the others. Sunni and Shia respondents rated the impact of the school curriculum as the significantly most important reason behind religious intolerance, whereas the Ahmadis and Christians rated hate literature as the most important reason. The results suggest that there is a need for further research into social factors that could reduce religious intolerance in Pakistan. Views of different religious groups need to be taken in consideration.