Freedom of assembly, as belonging to a sphere of fundamental political rights and freedoms, creates the basis for the functioning of a democratic society. This era has begun for the Polish citizens in 1990, with establishing the new statute on the assembly. Nowadays, the given freedom of assembly is detailed in the provisions of ordinary laws, headed by the 2015 statute on assemblies. The provisions specify the scope of this right, especially the issues of both passive and active right to assembly (to attend and to organize). The legislator introduces the types of assemblies (assemblies, cyclical assemblies, spontaneous assemblies) and clarifies the specific requirements, regarding also the organization procedure. The aim of the paper is to indicate the basic mechanisms that determine the legal institution of assemblies in its evolution since 1990. We also hope to deliver some answers to the question about balance between rationing limits and a need of expression.