This paper aims to show how Iranian pilgrims’ pursuit of devotional rituals and experiences turned into a humanitarian disaster on Iran-Ottoman borders and within Iraq borderlands on the way to Atabat and Mecca from the mid-19 century onward in the Qajar era (1789-1925). Drawing upon diverse sources in Persian, English, and Ottoman Turkish, this study sheds light on the fact that physical boundaries worked far beyond their geographical, political, and economic roles and illuminates how religious migration and associated rites and customs left pilgrims vulnerable to persecution and other forms of abuse. The study of religious mobility from the lens of the frontier helps us understand that although territorial boundaries provide socio-political and economic affordances, they also construct hostile institutionalized and non-institutionalized limitations. Demarcation is a means by which one can monitor the exploitation of travelers in different ways. Pilgrims’ traumatic experiences in borderlands range from inadequate transportation, climate variability, lack of food, inadequate health services, and contagious diseases, to assault, insult, plunder, bribery, and even murder by Ottoman officers and Bedouin Arabs in quarantines and/or in borderlands. The opening of the Suez Canal in 1869 and the development of railway routes in the Caucasus intensified religious mobility and expanded opportunities for Iranian pilgrims to perform the pilgrimage to Mecca and the holy Shi’a shrine cities of Iraq. Travel accelerated, yet pilgrims fulfilling this holy ritual faced unforeseen persecutions and challenges. Despite many hardships, people of all echelons of society continued to regard performing pilgrimages as an essential religious duty. The challenges, capacities, and spiritual values of these pilgrimage sites made them exceptional for pilgrims and demonstrate the extent to which pilgrimage played a fundamental role in Qajar society. These practices made pilgrims vectors of both natural hardships and human persecutions in multiple ways. This paper suggests that religious mobility in the form of pilgrimage across borders demonstrates multiple humanitarian aspects of frontiers and shows how the study of religious mobility and boundaries is inextricable. I argue that the religious mobility not only helped to account for the role of borders in victimizing pilgrims and turning certain Islamic rituals into socio-political opportunities for those who sought to instrumentalize people’s faith but also to explain various forms of abuse and neglect that religious pilgrims experienced at the hands of local populations and Ottoman officers alike. Keywords: boundaries, Iranian Pilgrims, Atabat, Mecca, persecution