In this work, the antioxidant content of the main forestry and logging by-products (bark, leaves, cones) found in Hungary was compared. The main goal of the study was to identify those wood species and by-products that have the highest antioxidant content and, thus, can be used in the future. The results contribute to sustainable forestry and waste management. The utilization of the by-products of farming (chaff, leaves, pomace, etc.) and forestry (bark, leaves, cones, etc.) is urged not only by stricter environmental protection aspects but also by increasing social responsibility. In recent decades, the research of bioactive compounds from by-products has gained special importance, especially the extraction possibilities of antioxidants: potential areas of utilization are as ingredients in food and cosmeceutical products, production of natural antioxidants and wood preservatives, and production of nanoparticles. The antioxidant capacity and total polyphenol content were measured using several methods. In the case of samples showing the best results, polyphenols were profiled by high-performance liquid chromatography and tandem mass spectrometry (HPLC-PDA-ESI-MSn). Results could contribute to elaborate future products and utilizations based on the extractives of the investigated Hungarian forestry by-products.