Freshwater fish are one of the most frequently translocated and introduced aquatic animal groups and exhibit higher establishment ratios than many other taxa. Introductions are usually irreversible. One of common non-native fish species in Turkey is the Gibel Carp,Carassius gibeliowhich was introduced in the 1980s and is now widespread. We tested dominant markers (ISSR and SRAP) for genetic characterisation of Gibel Carp samples collected from eight locations in western Turkey. ISSR and SRAP marker sets showed that the level of gene flow between these populations (N-m= 0.45 /N-m= 0.47) is low and that the level of genetic differentiation (G(ST)= 0.53 /G(ST)= 0.52) is high. Inter-population variation detected by ISSR and SRAP markers constituted half part of the population (46.88 / 50.00%), while the rest was at intra-population level. These results indicate that the present population of the Gibel Carp is the result of several colonization events originating from the different sources. The phylogenetic relationship among the populations suggest that there were two independent major introduction events, one in the Marmara Region and the other in southern Turkey.