In this study the current legal and market conditions of waste management in Poland are analyzed. The main legal basis for changes in the national municipal waste management system and their impact on the market situation in the last few years have been determined. Additionally, the important function of the selective collection and the key role of the separation of raw material fractions in waste sorting plants constituting the basis for the operation of Regional Municipal Waste Processing (RMWP) plants was underlined. Furthermore, the possibilities of developing electricity production technology in low and medium power modules using waste gasification techniques were emphasized. The stream of plastic mixture from municipal waste sorting was identified as problematic in the context of effective material recovery. Tests were conducted on the morphology of this waste stream from two sorting plants. In line with the literature data and as part of the analytical work, the properties of the plastic waste stream designated for recycling and the energy properties of the post-recycling plastic mixture were estimated. Tests results showed that the calorific value of this mixture reached 31.8 MJ/kg, whereas, ash and chlorine content equaled 2.7% and 1.1% of dry mass, respectively. These parameters indicate that the mixture as a high-calorific fuel component may be a valuable addition to refuse-derived fuel (RDF) produced from the over-sieve fraction of municipal waste. Concurrently, as a result of the development of waste gasification technologies with a high share of electricity production in low-medium power range plants, it is possible to integrate them with plastic recycling and RMWP plants in the Polish national waste management system.