Abstract In this study, two honeycomb catalysts with palladium and platina-palladium as active elements were used for an oxidation of products of incomplete combustion such as carbon monoxide (CO) and propane (C3H8) contained in flue gas produced by a small-scale stove. Catalysts were installed into the flue gas duct right behind the flue gas outlet of the wood log, and pellet stove. During the tests, the conversion rates of unburned pollutants were observed according to volume fraction of oxygen in the flue gas, space velocity of flue gas, temperature of flue gas at the catalysts inlet, and mass concentration of oxidized pollutants at the catalysts inlet. The CO conversion rates ranged between 37% and 95.4% (69% in average) in case of Cat A and 51.4% and 99.9% (96% in average) in case of Cat B. In terms of C3H8 conversion rate, Cat B proved higher effectiveness (25% in average), than Cat A (4% in average). The most significant parameters were determined. The significant influence of combustion phase on C3H8 conversion rate was observed in case of manually loaded stove.