The purpose of this study was to evaluate the influence of increased application rates of potassium on the physiological quality of seeds from different soybean cultivars. Seeds from two locations (Sao Gotardo, MG and Lavras, MG, Brazil) were used. After harvest, the seeds were sent to the Cen- tral Seed Analysis Laboratory of the Federal University of Lavras. We used a randomized design in a 4 × 6 factorial arrangement of four cultivars and six doses of potassium. All tests were performed with two replicates of 50 seeds (300 seeds per treatment). Germination, emergence under con- trolled conditions, accelerated aging, electrical conductivity, and tetrazolium tests were per- formed. Data were subjected to analysis of variance. In soybean seed production fields with high potassium content in the soil, higher application rates of potassium do not increase the physiolog- ical quality of seeds.