Food fraud is a common issue in the modern food industry. The undeclared use of foreign pro-teins in meat products is a major concern in this context. Oilseeds are ideal for this purpose due to their high protein content and since huge amounts of oil meals are obtained as a by-product of oil production. Therefore, a UHPLC-MS/MS method was developed for the simultaneous de-tection of chia, coconut, flaxseed, hemp, peanut, pumpkin, rapeseed, sesame, soy, and sunflower proteins in meat products. Potential tryptic peptide markers were identified by high-resolution mass spectrometry. The final twenty peptide markers selected, which are specific for one of the ten species targeted were each measured by multiple reaction monitoring. To the best of our knowledge, twelve new heat-stable marker peptides for chia, coconut, flaxseed, pumpkin, rape-seed, sesame and sunflower have not been reported previously.