A method for evaluating the thickness and uniformity of polymer coating (Celpril polymer) on pine (Pinus sylvestris L.) seeds was developed using scanning electron microscopy (SEM). The coating polymer was applied to the test seed lot until the highest subjective rating was reached by visual inspection using a seed coating quality scale. For the test seed lot, the mean coating thickness (9.5 ± s.d. 5.2 μm was calculated from 265 measurements on freeze fracture surfaces from 50 seeds. For a single seed the mean coating thickness, assessed from 180 profile plot measurements, was 9.9 ± 3.1 μm. Uniformity was determined by a systematically performed microscopy using a grid system to identify and locate parts lacking coating coverage. These coating damages showed a large variation in size. Larger damages (0.01-0.2 mm2) were examined in 10 randomly selected seeds and found to range between 3-8/seed. A more detailed analysis of the coated surface was conducted on a smaller surface area on a single seed. The numbers of pores (converted to pores/mm2) with a diameter of more than 1 μm ranged from 30-100 and the equivalent numbers for pores 0.3-1 μm in diameter were between 700-900. A similar analysis was used for cracks in the coated surface. The method that is established in this study should be especially useful for evaluating seed coating uniformity and thickness when the intention of the coating is to control seed hydration