The transformations in the funeral rites and beliefs associated with death among the Zoroastrians during their encounter with Islam represent a significant focus in examining the cultural and religious changes in ancient Iran. This research aims to investigate how the advent of Islam and the accompanying cultural exchanges influenced Zoroastrian funerary practices and attitudes towards death and the afterlife, and whether these changes indicate the preservation of ancient traditions, their rupture, or the emergence of a synthesis between previous teachings and Islamic concepts. The methodology involves a comparative analysis of Zoroastrian religious texts (such as the Avesta and Pahlavi writings) and Islamic texts (including Hadiths and early historical sources), the examination of archaeological evidence (like Towers of Silence and cemeteries), and the study of historical documents including Arabic and Persian chronicles. Preliminary findings suggest that during the post-Sasanian era, Zoroastrian funeral rites, such as the use of Towers of Silence, persisted to some extent; however, under Islamic influence, modifications occurred, including the simplification of rituals and, at times, the integration of Zoroastrian beliefs—like the concept of post-mortem judgment—with Islamic elements, such as the narration of the Bridge of Sirat. These transformations reflect a complex layering of the continuation of local traditions alongside adaptation to the new religious framework.