The beginnings of the Museum were two small rooms in a tenement house and a modest collection made up of donations from local residents or seized craft depots It was 1927. Visitors at that time could view mainly historical city documents and objects, such as the 'Leliwa' coat of arms, swords from the 16th century, coins and seals, and several hundred books. It was possible to relocate them during the war and thus they survived intact.

Until 1950, the Museum's only seat was the Town Hall, but today it has as many as eleven branches, not only in Tarnów but throughout the region. Six of them are located in the city:

The Museum of the History of Tarnów and the Region is a branch located in historic townhouses with Renaissance arcades. Following the grinder's tune, the tourist discovers the city's interesting history.

The Town Hall – The Old Art Gallery is located in the central part of the Market Square. The exhibition is presented in six themed rooms and is entitled 'In the Kontusz and by the Sabre'. It showcases the Sarmatian culture and associated militaria, everyday objects and portrait art specific to that time.

The Ethnographic Museum is a branch of the museum based in a historic suburban manor house with a garden and granary. The branch has been located there since 1984 and currently has around 5,000 exhibits. In addition to an exhibition on the culture of the Tarnów region,the world's oldest permanent exhibition on Roma culture, created in 1990, is also on display. The Museum's courtyard also houses the seasonal outdoor exhibition 'Tabor'. In addition to permanent exhibitions, the branch hosts temporary exhibitions on various themes, often related to ethnography, social movements or artistic activities.

The 'Panorama' Gallery is a permanent exhibition located in the railway station building, and deals with Jan Styka's 'Panorama of Transylvania'. The work was commissioned for the 50th anniversary of the Hungarian uprising against the Austrians. It was exhibited in several European cities, but then interest waned and the author cut the panorama into smaller pieces for commercial purposes. The Museum currently holds 22 of the 41 fragments that have thus far been found.

The Regional Memorial Education Centre is located in a former military barracks. This branch was established on the grounds of the former Memorial Chamber of the World Union of Home Army Soldiers. The originator of the institution was Brigadier General Zdzislaw Baszak, who was a soldier in the 16th Infantry Regiment. The unit was stationed in this building between the wars. In this branch you can see memorabilia and militaria related to the Tarnów soldier community.

The headquarters of the Museum are located in one of the townhouses at the Market Square. The ground floor and  the basement have rooms for temporary exhibitions.

There are branches outside the city limits:

Dębno Castle Museum is the only example of magnate residence architecture in the Małopolska region. Its construction lasted from 1470 to 1480. This late Gothic architectural gem has survived almost unchanged to the present day. The building was only modified twice: first a Renaissance renovation was carried out and then Baroque elements were added. During the November Uprising, insurgents hid there. The last owner left the castle in 1939. In 1977, the first exhibition of the castle's historic interiors was opened.

The Wincenty Witos Museum in Wierzchosławice consists of two parts: 'Old Homestead', i.e., Wincenty Witos' family home, and  Wincenty Witos' farm consisting of five buildings that he built between 1905 and 1913, called 'New Homestead'.

Zagroda Felicji Curyłowej (the Felicia Curyłowa's Homestead) in Zalipie is a richly decorated cottage by the artist Felicja Curyło (1903–1974), a propagator of colourful Zalipiecottage painting. The cottage looks more or less the same as it did during the painter's lifetime. Visitors can admire her beautiful ornaments on the fascias and walls, and on the kitchen stove  as well as the paper ornaments she made. 

The Jan Matejko Memorial Museum 'Koryznówka' in Nowy Wiśnicz is a wooden manor house from the mid 19-th century. It owes its authenticity to the Serafiński family, who have farmed on the manor since the estate's inception. Jan Matejko spent the time of his engagement here and often visited the owner of the manor, Leonard Serafiński, who was his friend. The artist was fond of the 'Koryznówka' area and left many sketches of the buildings of Nowy Wiśnicz as well as many caricatures. During the Second World War, the manor was part of the underground network and provided shelter for people in hiding. It was here where Captain Witold Pilecki went into hiding after his daring escape. The manor house opened its doors to visitors in 1981.

The Dołędze Manor Museum is a wooden noble manor house from 1848. At the turn of the 20th century, visitors included Adam Asnyk, Stanisław Wyspiański and Lucjan Rydel. The manor was donated to the museum by its last owner, Jadwiga Wolska-Tumidajska  in the 1970s. Today, the Museum's interiors are arranged just as they were in the mid-19th century.