Summary Seed size can influence germination, growth and yield formation of crops. A two-year field experiment was conducted in eastern Austria in 2012 and 2013 with two cultivars (Paula and Tatum) and four seeds size (< 2.5, 2.5–2.75, 2.75–3.25 and > 3.25 mm) to assess the effect of seed size on soil coverage, yield, yield components, nitrogen concentrations and nitrogen yield of spring malting barley. Soil coverage during the vegetation period was higher with a larger seed size in one year. Above-ground biomass and grain yield were not affected by seed size but differed between varieties and years. Seed size, however, affected the yield components. Both varieties had a higher ear density with the largest seed size compared to the smallest seed size. Higher ear density resulted in a lower thousand kernel weight. Grains ear-1 did not differ between seed sizes. Harvested grain fractions, nitrogen concentrations and nitrogen yields were also not affected by seed size.