Euthynnus species are epipelagic migratory tuna species, with global distribution. They occur in the open waters but usually remain close to the shoreline. In present study, historic demography and phylogenetic relationship of Euthynnus species were examined using sequence data from portions of the mitochondrial COI gene. A total of 35 sequences were retrieved from NCBI. Mismatch distribution analyses suggested a late Pleistocene population expansion of E. affinis and E. alletteratus. Neutrality test for E. alletteratus fails to reject the null hypothesis of neutral evolution while COI sequences of E. affinis are found to be at genetic equilibrium. Phylogenetic analysis suggest that E. alletteratus is the most ancestral species while E. affinis is more closely related to E. lineatus than E. alletteratus.