Wood quality has been an ongoing concern for specialists, which has become increasingly important in the current context, where the demand for wood is increasing and forest fires are more frequent and violent. The article aims to evaluate the quality of wood in trees affected by fires and the negative impact of these phenomena on the speed of wood degradation, as a result of the weakening of the trees due to the action of disturbing factors. Investigations were carried out using modern techniques on the beech trees (Fagus sylvatica L.) remaining in an area affected by a litter fire in 2017. Measurements were taken were made with the Arbotom Rinntech sound tomograph, the IML F-500 Resi resistograph and the Pressler core sampler to observe the quality of the wood inside the trunk. It was found that all the trees are in various stages of decaying the tomograms being able to highlight the severity of the defects only in the case of the total destruction of the wood structure as a result of the action of xylophages fungi, whose harmful influence is more pronounced when the injuries sustained by the trees from the fire were greater. Although the trees tried to close the fire wounds through their own defense mechanisms, the destructive action of the fungi intensified with the time.After the forest fires, for quickly and clear results regarding the internal quality of the wood could be used the resistograph. For valuable trees could be used the tomograph, but the measurements have to be taken only by qualified operators.