The Casino Maltese started off as the treasury of the Order where the accounts, contracts and records of the Treasury were kept and was known as the Casa del Commun Tesoro.

The property consists of a large, two-storied corner building containing a number of shops at ground floor level as it was customary during the 16th and 17th centuries for large buildings to have shops at ground floor. In the 19th century, during the British rule the building was converted into the Grand Hotel.

In the first decade of the 20th century it was converted again into the Casino Maltese, which is a gentlemen's club of high repute, as it remains to this day. The building suffered heavy damage during the blitz in 1942 and was partly demolished by a bomb which fell in the courtyard and destroyed the grand stairway, but this was rebuilt.

The building contains a number of features such as a unique sundial and calendar combination on the exterior wall overlooking Triq ir-Repubblika, a suspended decorative and gilt ceiling, the grand staircase, a large central courtyard and an open balcony at first floor level around most of the building.

Mepa scheduled the Casa del Commun Tesoro (now the Casino Maltese) as a Grade 1 national monument as per Government Notice number 276/08 in the Government Gazette dated 28 March 2008.