: Influence of the use of chestnut starch as a binder filler in plywood technology. Fillers play a crucial role in the production of plywood glues, providing enhanced performance and stability to the end product. Plywood, being a composite material, requires fillers to improve its mechanical properties, adhesion, and overall quality. One common filler used in plywood glues is calcium carbonate. It acts as a bulking agent, increasing the volume and density of the adhesive mixture while reducing production costs. Calcium carbonate also enhances the glue's viscosity, ensuring proper bonding and uniform application during the plywood manufacturing process. Another widely used filler is rye or wheat flour, which consists of finely ground grains. The flour not only improves the adhesive's viscosity but also contributes to the overall strength and stability of the plywood. It helps to prevent warping and enhances dimensional stability, making the final product more durable. Additionally, other fillers like talc or clay minerals may be incorporated into the glues to improve their adhesive properties and increase moisture resistance. Chestnut starch is a type of vegetable flour made by grinding edible chestnuts into a powder. It has a different texture and properties than traditional wheat or rye flour. When used as a binder filler in plywood technology, it can be biodegradable and environment-friendly. In the study, there were produced five types of plywood with 0, 1, 5, 10, and 20 parts by weight chestnut flour and one reference. All samples were produced in laboratory conditions and the selected mechanical and physical properties of the produced boards were studied. The mechanical properties of the boards increased with the addition of chestnut flour. In some tests, the results even met the highest requirements of European standards for plywood. According to this finding, a well-chosen addition of chestnut flour could be positively considered in plywood production.