The number and structure of red mullet chromosomes (Mullus barbatus Linnaeus, 1758) were investigated and the species karyotype was analyzed. Specimens were obtained by trawl from the coast of Zonguldak, Turkey. A colchicine solution, 0.1 mg/g of body weight, was intramuscularly injected dorsally, and intraperitoneally injected ventrally. Slides were prepared from gill and fin epithelial tissues. Results of the conventional staining method showed that this species has 2n = 44 diploid chromosomes. © TÜBİTAK.