The library was founded in 1616, but since 1675 it has been housed in the “Esnoga”, the same monumental complex that is home to the Portuguese Synagogue. In 1889, former librarian David Montesinos donated his entire personal collection to the library, on condition that it would be accessible to all. The library has since been known as the "Ets Haim - Livraria Montesinos".
The collection of Ets Haim Library has been granted UNESCO World Heritage status. Its literary works encompass all aspects of Jewish scholarship, and as well as many aspects of literature, history and the natural sciences. Of the 20,000 volumes, roughly 65% are in Hebrew.