The pathway of ochratoxin A (OTA) biosynthesis has not yet been completely elucidated. Essentially, two kind of genes have been demonstrated to be involved in the biosynthesis of OTA. One of them is the nrps gene encoding a non-ribosomal peptide synthetase (NRPS) which catalyzes the ligation between the isocoumarin group, constituting the polyketide group of OTA molecule, and the amino acid phenylalanine.Here we describe a conventional PCR method developed for the detection of OTA-producing molds belonging to Penicillium and Aspergillus genera by Luque et al. (Food Control 29:270-278, 2013). This method is based on the OTA nrps gene of Penicillium nordicum. It produces a specific amplicon of 459 bp and its functionality in naturally infected samples was also demonstrated.