Known as the "Island of the Mad," for 250 years the Island of San Servolo was the official mental asylum of Venice.

Run by the religious order San Giovanni di Dio, the asylum opened in 1725 with the order that all insane men be relocated there. In 1798 it began to accept women as well.

Over 200,000 patients were admitted to the asylum, and most would never leave. In 1978, following a change in Italian law, the asylum was closed and the Venice government created the "Istituto per le Ricerche e gli Studi sull´Emarginazione Sociale e Culturale" (Institute for the Study of Social and Cultural Marginalization) to preserve the documents related to the history of the hospital.

In 2006, it was reopened in its current form, as a museum dedicated to the history of the asylum. The museum houses the equipment from the mental asylum, as well as the anatomical theater, though the theater is a recreation using the original equipment since the actual room now provides a different use. It is divided into nine sections: the Laboratory, the Ambulatory, Didactic Products, Sickness Therapies, Straightjackets, the Sick, Lodgings, Pharmacy, and Anatomical Theater.

The archives hold photo albums of patients from 1874 through to the 20th century, including 13,695 glass plates, and the library holds a collection left by San Servolo and San Clemente Psychiatric Hospitals, such as religious works from the 16th to 18th centuries and more recent medical and scientific works. There is also an extensive park with rare plants and trees which once supplied the pharmacy.

The island also houses Venice International University, opened in 1995.

Another asylum lies abandoned and off limits in the Venetian lagoon on Poveglia Island, one of the city's many plague quarantine stations. Near Poveglia, mass graves of plague victims were found on the quarantine islands of Lazzaretto Nuovo and Lazzaretto Vecchio.