Quebec wood species, jack pine (Pinus banksiana Lamb.) and aspen (Populus tremuloides Michx), were thermally treated in an industrial furnace using 'Bois Perdure' technology. The species were heated from room temperature up to their respective maximum heat-treatment temperatures. The mechanical properties, dimensional stability, and mold resistance of these species were determined and compared with those of untreated wood. This information is essential for the users of these new products. Results indicate that modulus of rupture (MOR) of heat-treated jack pine and aspen decreased, whereas modulus of elasticity (MOE) of the same heat-treated species increased, respectively. All the tests were carried out with a different set of specimens. Results show that the dimensional stability of heat-treated jack pine and aspen was improved considerably after heat treatment. Mold resistance of heat-treated jack pine was improved compared to the untreated sample; mold resistance was improved for heat-treated aspen; however, it was not significantly different from the untreated aspen.