In the early years of the facility majority of the monuments were modest collections of folk material and spiritual culture. Fundamental changes in the functioning of the Museum brought only 1975, when as a result of transformation of the country, Biala Podlaska became the seat of provincial authorities. Increased budget establishments paid off a significant increase in collections, began to form the first collections. In 1975 he entered in the inventories of museum objects was only in 2116, but already in 1982 Museum collection numbered about 17 000 units, and in 1990 their number increased to 21 000 exhibits.
With purchases formed the thematic collection of Polish painting under the name "Horses, riders, teams in Polish painting of the century". National air painting in Janow Podlaski organized regularly in the years 1975-1998 resulted in a significant collection of contemporary painting. Gathered substantial numismatic and medalist. Systematically enlarged historical collections, gathering documents, archives and other items related to the past of the town and the region. Field studies and numerous folk art competitions have contributed to a steady increase ethnographic collections.
In the years 1980-1995, mainly due to the customs confiscations, they gathered numbering around 1,400, so one of Poland's largest collection of Russian icons XVII-XIX centuries. The collection of history and art department hit precious gifts the family of Alexander Próchnicki, Bialski painter, architect and regionalist and numerous documents, photographs and old memorabilia, donated by Professor Stefan Kryński of Gdansk. In 1995, he obtained the legacy of the creative achievements of famous painter of Dąbrowicy Little Basil Albiczuka, and in 2005 a significant deposit Bialskie paintings and prints by Zbigniew Karpinski, a professor at Academy of Fine Arts in Wroclaw. A valuable contribution to enriching the iconography of the city brought acquired in 2006, the work of Tadeusz Różyckiego Bialski watercolorist, offered on the occasion of the organization of the exhibition by the artist's nephew prof. Kiejstut Bereźnicki, and Janusz cripple and Danuta Dunajko Andrzejuk. Now, after 40 years of operation of institutions, the number of collections of the Museum of Southern Podlasie in the White Podlasie is about 40 000 exhibits.