The aim of the study was to assay by PCR screening method whether the processing and the thermal stress have any influence on the feasibility of the detection of genetically modified DNA in different kinds of processed meat products such as sausages, liver cans, ready-to-eat hamburgers. The model meat products have been prepared with soybean meal spiked with RR (Roundup Ready) soybean meal in 0.5%, 1%, 1.5% and 2%. The samples were prepared under industrial circumstances. The assay was based on the detection of the specific part of the 35S promoter and the NOS terminator sequences. The modified PCR method was shown to be suitable for screening of GMOs in raw and also in moderately and highly processed meat samples when extreme heat treatment and pressure were used for the preparation of meat products. Half a percent RR soy contamination could be detected even if the food products underwent high temperature treatment.