Abstract The objective of this work has been to develop a suitable methodology based on mitochondrial cytochrome b gene (cytb) to allow the identification of animals species used as raw material in the manufacture of processed food. In some cases, more detailed information on the kind of food sample found in the stomach of a victim may be of particular importance. A number of specimens of processed food with bovine, pork and chicken origin were analyzed. DNA was extracted by two methods: (1) Cell lysis using proteinase K and SDS, and phenol-chloroform DNA purification; (2) NucleoSpin Food (Macherey-Nagel™). PCR amplification of 358 pb of the cytb was done. The species of the samples were identified by aligning to the cytb gene sequence entries using BLAST of the National Center for Biotechnology Information. Both the DNA extraction procedures yielded enough DNA to be analyzed by PCR. Sequences obtained were searched against nucleotide sequence database (GenBank). With this procedure, it is possible to classify each sample correctly according to its biological species.