The museum's collections were formed from Esztergom St. Benedictine Grammar School’s antiques and coin collections from the 1860’s and the antique collections of Bishop Nándor Knautz and others (Rezső Rényi, Lajos Némethy, Ferenc Brenner, Ferenc Einczinger, Elemér Reviczky, etc.) Jákó Ferenczy Benedictine director founded the local "Museum Society” in 1875. In 1891-92 Viktor Récsey and Nándor Knauz carried out significant excavations in Esztergom. 

Between 1913 and 1933, the museum was located in different buildings, then moved back to the Bibliotheca building, where he remained until 1989.

After World War II the collection was nationalized (it got the name "Balassa Bálint Museum") and László Zolnay was appointed director (1951-1959) to the institution, who was followed by Zoltan Nagy (1961-1969).

The above mentioned directors exercised professional supervision over other ecclesiastical collections (Christian Museum, Treasury), even from 1961 on, —when the building complex of the royal palace formerly owned by the church was nationalized and attached to the Balassa Bálint Museum —can be visited. Since 1963, the Castle Museum has been operating as an independent museum with a research area in the territory of the Esztergom Castle.

From 1969 to 2012, more than 40 years dr. István Horvath, an archaeologist managed Balassa Bálint Museum. In 2013, due to the reorganization of the Hungarian museum organization, the museum become an affiliate of the Hungarian National Museum, and the Castle Museum and Balassa Bálint Museum were combined in one institution.

Museum's current collection area is the historical half of Esztergom County to the south of the Danube. Its main activities include the area of archaeology, ethnography and local history, but its science, fine arts, as well as decorative arts collections are also significant. The library keeps 26,000 volumes and the collections include more than 220,000 pieces of objects.

Our institution has been engaged in museum education activities since 2008: there are historical events, history lessons, arts and craft workshops, etc.

The old permanent exhibition was closed and disassembled in 2013 and replaced by a special visual storage exhibition in our building in Mindszenty square. The museum plays an important role in Esztergom city and the county's cultural, scientific life and in their public education.