This study was aimed at investigating the levels of the natural preservatives of benzoic, sorbic and propionic acids in cereal grains, nuts and seeds. Benzoic and sorbic acid were analyzed by high-performance liquid chromatography with a diode-array detector (HPLC-DAD) and further confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), whereas propionic acid was analyzed using a gas chromatography-flame ionization detector (GC-FID) and further confirmed by gas chromatography-mass spectrometry (GC-MS). Benzoic, sorbic and propionic acids were found in 44, 22, and 550 samples out of 702 samples, respectively. From the total of 702 samples. The concentrations of benzoic, sorbic and propionic acid were ranged from not detected (ND) to 23.74 mg/L, from ND to 7.90 mg/L, and from ND to 37.39 mg/L in cereal grains, nuts and seeds, respectively. The concentration ranges determined in this study could be used as standard criteria in the process of inspecting cereal grains, nuts and seeds for preservatives as well as to address consumer complaints or trade disputes.