This study uses Geographical Information Systems (GIS) to estimate woody biomass supply and demand in Northeast Italy. Demand is estimated using census data on boilers and supply calculations are derived from data on timber harvests and mill operations. The analysis is done with GIS using Large Scale Analysis at a broader resolution (for the entire region) and Small Scale Analysis at a finer resolution (for the Primiero valley only), with added information on tree species, road networks and logging systems. From large scale analysis demand results to be about 163 000 MWh, corresponding to about 71 000 tonnes per year of fuel, with a moisture content of 50 percent. As shown by results from a small scale analysis, the Primiero valley has a deficit of 21 400 MWh. A more thorough analysis shows that 93 percent of logging operations can be performed with cable cranes and that high quality chips derived from forest biomass amount to only 335 MWh of energy (20 percent of the total). The deficit calculated at a small scale confirms the value obtained in the large scale calculation. Analysis of the demand-supply balance will be helpful for decision makers and politicians and should be taken into account when allocating subsidies for new boilers or district heating. (C) 2010 Elsevier Ltd. All rights reserved.