The Muhammad Ali Hamdani Collection in the Library of The Institute of Ismaili Studies represents a large segment of the library collected over seven generations by an eminent family of scholars from the Da'udi Bohra community in India and the Yemen. The bulk of the manuscripts are Ismaili religious writings, but there are also a good number of interesting books of general Islamic, or indeed secular content, and these give a rare insight into the whole cultural range of a learned family of Indian religious scholars. The overwhelming majority of the books are in Arabic, but there are also a small number in Persian and in Bohra da'wat language (lisan al da'wat), Gujarati in Arabic script. Most of the manuscripts were produced in India, but some of the most interesting ones are from the Yemen, the ancestral home of the Hamdani clan (the oldest of these is from the 14th century CE, or perhaps earlier). The catalogue contains detailed descriptions of the manuscripts in this Hamdani collection, discussing both the content of the works and the codicological features of the manuscripts. The introduction contains also a comprehensive history of the Hamdani family.