Levoglucosenone (LGO) (6,8-dioxabicyclo[3.2.1]oct-2-en-4-one) is commonly produced by synthetic preparation and catalytic pyrolysis of cellulose, both. Feasibility of LGO production from birch lignocellulose (LC) as well as birch and pine wood was studied by analytical pyrolysis. We found that the presence of elevated amounts of lignin and the full or partial elimination of hemicelluloses favor LGO formation during orthophosphoric acid catalyzed LC pyrolysis at 375 °C. The yield of LGO reached up to 29–30 rel.% from LC pyrolysis products. A known positive effect of lignin on the thermal stability of cellulose during the heating stage prior to the stage of the active decomposition of cellulose was demonstrated. An increased LGO yield from the cellulose mass unit in bulk of wood and LC in comparison with isolated cellulose was observed. The process of LGO production is promising as a method for LC utilization in a complex enterprise of wood hydrothermal processing into chemicals.