<p>This paper explores the legitimacy of sex reassignment surgery within contemporary Shiʿi Islamic jurisprudence, with a particular focus on post-revolutionary Iran. Through an analysis of fatwas issued by prominent Shiʿi marājiʿ (religious authorities), the study examines a wide spectrum of legal and theological views on gender transition. While classical Islamic sources do not explicitly address transsexuality or gender identity, modern scholars have issued divergent rulings based on their interpretation of Qur’anic verses, hadith, and jurisprudential principles. The paper highlights the pioneering role of Ayatollah Khomeini, whose fatwa legitimizing sex reassignment surgeries, significantly influenced Iran’s legal framework and enabled state-supported procedures for trans individuals. It also investigates the distinctions scholars make between intersex (hermaphroditic) conditions and cases of gender dysphoria, and how these shape permissibility. The study further engages with ongoing debates among marājiʿ concerning the nature, completeness, and theological implications of contemporary sex reassignment techniques. While some authorities accept sex reassignment surgery as a medical treatment and an affirmation of one’s “true” gender, others regard it as a superficial alteration lacking legal and religious effect. The analysis reveals a jurisprudential field in flux, shaped by evolving medical science, social realities, and the enduring principle of accommodating human needs within Islamic legal thought.</p>