The origins of the Confraternity date back to the early 15th century. After alternating fortunes and after having taken various names, in 1864 the organisation became the Devout Misericordia of Buonconvento and adopted new statutes. The Museum contains mainly works of art and liturgical objects, but there is also a collection of materials pertinent to the Confraternity's relief activities. The scientific collection includes objects from the 19th and 20th centuries, among them a first-aid kit with medicines and various glass objects, including a urinal for women, and one of the first ambulances ("emergency cart") utilised by the Brotherhood.

On September 14, 2002, upon completion of work carried out for the structural and functional restoration of the premises, the new museum itinerary was inaugurated. It displays, in addition to the objects from the Confraternity's collection, those coming from other institutions in the territory.