The article describes the results of combustion tests of tree leaves as one of the possible methods of their management after they have been collected from built-up areas. As a result of combustion it is possible to recycle/gain energy from the plant biomass. The clue of the method is based on the estimation of calorific value of material for leaves of chosen tree species from built-up areas according to the method regulated by the standard PN-EN ISO 1716. The method of measurement lies in complete combustion of a specified mass of material inside an atmosphere of oxygen under pressure in the Calorimeter Bomb in stirred water bath and measurement of water temperature increases. The analysis was performed on samples of shredded leaves or of leaves formed into briquettes. The tests proved that the heat of combustion was different for leaves of various tree types and that leaves in loose shredded form have a higher calorific value of material than those formed into briquettes. The average value of heat of combustion reached 14 kJ g-1 for leaves formed into briquettes and for 15,3 kJ g-1 for loose shredded leaves. The highest calorific value of material was recorded for leaves of white chestnut and those of red oak, and the lowest for leaves of lime-tree and maple.