Temporary distancing enables us to examine the difficult and contradictory time of museum sphere development in the USSR, which is known in history as Gorbachev’s perestroika and glasnost. The article attempts to demonstrate the expansion of the museum network in Soviet Belarus, to trace the process of its profile differentiation, and to trace the branching of museums during this time using archival sources from the collections of the Ministry of Culture of the Belarusian SSR, published statistical materials, as well as periodicals. The source base utilised made it possible to examine public efforts and state policies in the area of museum life. One of them is the public discourse of the late 1980s and early 1990s regarding who owns the cult artistic heritage that museums have preserved during the years of anti-religious actions. The author highlights the increase of museum collaboration with Belarusian collectors while listing and discussing museum innovations from the perestroika and glasnost era. Between 1985 and 1991, there was a significant shift in the development of Belarusian museums, which gradually became more focused on international contacts. The author notes that when examining the beneficial improvements in museum life during the perestroika and glasnost era, it was during this time that there was a final, normative reluctance to record and publicize the accomplishments of Soviet society. The state policy aimed at the development of Belarusian culture and the cultures of the national communities of Belarus as an integral part of universal human culture was reflected in the filling of fresh content in all areas of work of Belarusian museums. The material and technological foundation of museums has been damaged, and their budgetary support has been constrained, by the country’s deteriorating socioeconomic position. This called for the adoption of new management techniques, organizational structures, and technological advancements, which happened following the failure of the Soviet Union. In general, the article expands the existing ideas in historical museology about the era of perestroika and glasnost, its role in the expansion, democratization, and professionalization of museum activities.