The objective of the present study was to investigate the following questions: Composition of parental and transgenic (Bt) maize seeds, digestibility and nutritional value of both maize lines in pigs, grower-finisher performance of pigs fed with diets rich in parental or transgenic maize and fate of foreign-DNA-fragments in pig bodies. Compared to the parental line, the chemical composition and digestibility of crude nutrients and energy content were not significantly affected by the genetic modification of maize. Therefore, from the view of a nutritional assessment, the genetically modified maize can be regarded as substantially equivalent to the parental maize line. The results of the grower finisher performance trial with forty-eight pigs confirm equal performance among growing-finishing pigs fed parental or genetically modified maize containing diets. The passage and fate of ingested DNA in 48 pigs fed with diets containing parental or transgenic maize were examined. Animals were slaughtered in different groups after feeding the last maize-containing diet. DNA extracted from tissues and gut contents was examined by PCR for the presence of plant DNA and for any transgenic material. Recombinant DNA was detectable in the intestinal contents up to 48 h after the last feeding of a diet containing the transgenic maize. Recombinant or maize-specific DNA was not detectable in tissue samples of pigs. In contrast, plant DNA fragments were detectable in the investigated pig tissues as well as in a raw meat product thereof.