Najīb al-Dīn Muḥammad b. ʿAlī b. ʿUmar al-Samarqandī (d. 619/1222) was a medical doctor and author of several works on medicine. He wrote on various subfields within medicine, including cardiology, pharmacy, and pathology. He lived in Baghdad, evidence of which comes from a comment about one of the hospitals in Baghdad where he either worked or studied. His works were commonly known as “al-Najībiyyāt” or “al-Khamsa al-najībiyya” (the works of Najīb, or the five works of Najīb). Based on an early exemplar, it seems that he began writing medical treatises as early as 594/1197-8. His work Kitāb al-asbāb wa l-ʿalāmāt (الأسباب والعلامات) was subject to a commentary by Nafīs b. ʿIwāḍ al-Kirmānī (d. 827/1424) and ʿIzz al-Dīn Suwaydī (d. 690/1292), and was one source for the late Persian medical text Ṭibb-i Akbarī by Arzānī (d. 1112/1700). His writings were widely circulated and translated in later centuries, there being evidence that they were copied in hospitals in Cairo and Khwārazm. Samarqandī was killed at the hands of the Mongols during the invasion of Herat in 619/1222 (whence his sobriquet al-Maqtūl). The fact that he died in Herat suggests that he was originally from the region, particularly since his nisba al-Samarqandī indicates that he was originally from the city of Samarqand in present-day Uzbekistan.