The majority of the global feed market is dominated by the Roundup Ready 40-3-2 transgenic soybean varieties developed and marketed by Monsanto Company, which are characterized by tolerance to glyphosate, the active ingredient of the Roundup herbicide. It should be remembered, however, that soybean is one of the major allergens which may affect animal health. The aim of the study was to compare allergenic properties of globulins derived from genetically modified (GM) soybean imported from the USA and conventional soybean developed in Poland. Analyses were performed by measuring porcine lymphocyte proliferation in in vitro cultures. It turned out that both genetically modified and conventional soybean proteins caused immune response at the level of negative control. A slight increase in relation to the negative control was observed in the case of 7S and 11S fractions derived from the GM meal and 7S fraction isolated from Nawiko meal.