The concept of blood circulation, a cornerstone of modern physiology, is often attributed to William Harvey’s work in the 17th century. However, the historical origins and philosophical underpinnings of circulatory theory can also be traced to earlier traditions, notably the Unani system of medicine. Unani medicine, which has its roots in Greco-Arabic science, offers a profound comprehension of the human body, with blood (Dam) being one of the four essential humors. Foundational ideas on the heart, vessels, and blood flow were created by notable Unani scholars including Buqrāt (Hippocrates), Jalinūs (Galen), Ibn Sīnā (Avicenna), Abū Bakr Moḥammad Ibn Zakriyā Al-Rāzī (Rhazes), and Ibn Al-Nafīs. In alignment with the contemporary understanding of pulmonary circulation, Ibn Nafis, who is widely regarded as a prominent and highly influential figure within the traditional Unani medical framework, put forth a significant hypothesis regarding the journey of blood circulation. Specifically, he suggested that blood circulates from the right heart chambers to the left heart chambers through the intermediary of the lungs. This ground-breaking theory, which notably predates the discoveries of William Harvey, stands as a remarkable testament to the expansive breadth and depth of Islamic medical knowledge during that era. Ibn Nafis's pioneering work not only sheds light on the complexities of blood circulation but also serves as a crucial element in acknowledging the valuable intellectual contributions of Unani medicine to the field of anatomical sciences. Furthermore, it is imperative to incorporate his unique and insightful perspectives into the broader narrative of medical history on a global scale, recognizing the lasting impact of such contributions on the evolution of medical understanding and practices across diverse cultures. This research explores the original insights on blood circulation found in classical Unani texts, with a focus on the synthesis of anatomical, physiological, and philosophical knowledge that anticipated several principles of modern circulatory science. With the revival of anatomical dissection in European universities it laid the groundwork for later scientific breakthroughs.