Selected physical parameters of common hornbeam nuts were determined in five batches of nuts harvested from seed tree stands in northern Poland. The results were used to calculate the arithmetic and geometric mean diameters, aspect ratio, sphericity index, volume and density of each nut. The above parameters were compared by analysis of variance, correlation analysis and linear regression analysis. Habitat conditions had a greater influence on nut plumpness than the age of the tree stand. Nut width was highly correlated with nut mass, and the above observation can be used in the process of separating nuts into mass categories. When two mesh screens with 5 mm and 6 mm openings are used, nuts will be separated into a fine-sized fraction containing 71.4% of nuts with reduced plumpness, 24.1% of moderately plump nuts and 1.8% of plump nuts, and a coarse-sized fraction containing 2.0% of nuts with reduced plumpness, 43.6% of moderately plump nuts and 54.4% of plump nuts.