Production of woody biomass-based energy, mainly by using fuel wood, is a common way of forest utilization in selected South-Eastern European countries – Croatia, Bosnia-Herzegovina, Serbia and Former Yugoslav Republic of Macedonia. Due to specific forest ownership patterns in the region, state owned forests are the most important source of all forest assortments, including woody biomass. Having in mind the increasing energy needs on the global scale, particularly those for energy from renewable sources, private forests may play an important role in terms of wood mobilization and energy production from woody biomass. The purpose of this research was to identify the willingness of private forest owners in selected countries to supply woody biomass for energy as well as to identify the factors that influence it. The survey data collected in 2012 from 1.400 private forests owners (random samples of 350 private forests owners in each of the four countries), show a relatively high degree of willingness (38–55% of the respondents) to manage their forests in order to produce woody biomass. Furthermore, the results, demonstrated that the willingness of private forest owners to supply woody biomass was namely influenced by age in analysed countries. The models found that relatively younger owners were more likely to supply woody biomass. An adequate institutional and financial support to private forest owners and the designing of an appropriate mix of forest policy instruments are necessary for a better wood mobilisation and the triggering of woody biomass supply from private forests in selected South-Eastern European countries.