The results of a study on the isolation of microorganisms decomposing styrene are presented in this paper. Bacteria showing such an ability were isolated from the bed of an experimental biofilter purifying exhaust gases from a cable factory's coil-wire varnishing division. In order to isolate the bacteria, styrene was introduced into the medium in the amounts of 0.5, 1.0, 1.5 and 2.0 ml/l. Also, the air in the desiccators, where the microorganism culture was performed, was saturated with styrene. The study also describes the ability of isolated bacteria strains to degrade styrene. These additional studies were carried out in flask cultures (periodically) and gas wash bottle cultures (semi-continuously). isolated bacteria metabolized styrene that was contained in the air at maximum concentrations of about 1300 mg m^-3. The most active bacterial isolates for styrene utilization were: Streptomyces halstedii, Bacillus megaterium, Sphingobacterium spiri-tivorum, Bacillus cerus. The efficiency of styrene biodegradation was up to 100%, and the rate was about 23 g m^-3 h^-1.