The new classification system for the reaction to fire performance of building products in Europe, the so-called Euroclass system, has been applied to five different types of wood products: wood-based panels, structural timber, glued laminated timber, solid wood paneling and cladding, and wood flooring as being products with known and stable fire performance. Most wood products fall in classes D-s2, d0 or Dfl-s1 (for floorings). Some products may also fall in the main classes C or E. Testing has been performed according to EN 13823 SBI Single Burning Item test, EN ISO 9239-1 Radiant panel test, and EN ISO 11925-2 Small flame test. More than 100 wood products in different end use applications have been studied. With the experimental evidence, clear relationships between the main Euroclass fire performance parameters and product parameters (such as density and thickness) have been demonstrated. The new European system for the reaction to fire performance classes consists of two sub-systems, one for construction products, i.e., mainly wall and ceiling surface linings, and another similar system for floorings. The main parameters influencing the reaction to the fire-retardant characteristics of all wood products are product thickness, density and end-use conditions, such as substrates or air gaps behind the product.