This report is the first molecular characterization of the facultative myiasis agent Eristalis tenax collected from cattle barns in Kayseri province of Central Anatolia, Turkey. A total of 10 adult fly specimens were included in the study. All flies were identified as female adults of E. tenax by morphologic characteristics under a stereomicroscope. The barcode region of the mitochondrial cytochrome oxidase 1 (CO1) gene was amplified with PCR from the genomic DNA extracts of E. tenax specimens for molecular identification and phylogenetic analyses. There was no polymorphism among the CO1 sequences of all isolates leading to the detection of a single haplotype for E. tenax. Haplotype and nucleotide diversities in the CO1 data set comprised of the sequence of the detected haplotype and the published sequences of E. tenax from different countries in GenBank were determined as 0.775 and 0.002, respectively. The newly characterized haplotype in this study clustered with the haplotypes from Australia and Canada in a monophyletic clade and exhibited a 100.0% identity to the Australian E. tenax isolate (JN991985). Interspecific genetic differences between E. tenax and other Eristalis species were in the range of 5.7% to 7.9%.