The study discusses an experimental method for treatment of high strength domestic sewage on biofi lters fi lled with polyurethane (PUR) waste in the form of trims of upholstery foam. We determined eff ectiveness of two biological preparations containing eff ective microorganisms in elimination of organic and biogenic compounds, indicator bacteria and total suspended solids from the sewage pretreated in a septic tank. After four months of work under a hydraulic loading of 76.4 mm•d -1 we found the fi lter with 60 cm foam layer to be the most effi cient in the elimination of BOD 5 , COD Cr , NH 4 + -N and coliform bacteria. An average reduction in these pollutants reached 79.4%, 67.8%, 58.0% and 88.0%, respectively. Vertical fi lters fi lled with trims of upholstery foam and supplied with eff ective microorganisms ensured favorable conditions for development of heterotrophic and nitrifying bacteria without any need for additional aeration.