The Institute of Manuscripts of the Azerbaijan National Academy of Sciences has a collection of 390 early medical documents, which include 363 manuscripts dating from the 9th century. Most are written in Arabic - the literary script of the day. Of these, 70 are in the Arabic language, 71 in Turkic languages (Turkish, Tatar, Kumyk, Uzbek), and the remainder in Persian.  In 29 July 2005, UNESCO officially included three medieval medical manuscripts from the Institute of Manuscripts of the Azerbaijan National Academy of Sciences in the register of the Memory of the World Program, which comprises unique and irreplaceable written monuments of humankind. The Certificate confirming this decision was presented to the Institute of Manuscripts by Dr. K. Matsuura, the head of UNESCO. These manuscripts are described in the present paper.