In order to be able to assess the impact of invasive fish on native species and ecosystems, it is important to know their existing distribution areas. The Meric River, which is fed by some other rivers from Greece and Bulgaria, is the 'open door' where invasive species enter Turkish inland waters through European part of Turkey. Due to this need, it was aimed to determine the new distribution areas of invasive C. gibelio, L. gibbosus, P. parva and G. holbrooki in Turkish Thrace. The field surveys were conducted in a total of 135 stations in Marmara and Meric-Ergene basins. Carassiusgibelio and G. holbrooki were the species that expanded their distribution range the most; C. gibelio was captured from 24 stations and it was recorded as new to 15 localities while G. holbrookiwas captured from 17 stations and it was recorded as new to 15 localities. Lepomisgibbosuswas collected from Rezve and Sultanbahce streams in Marmara Basin and it was recorded as new to these localities. Pseudorasboraparvawas collected from 10 stations and it was recorded as new to 9 localities.