Scardinius is a genus of ray-finned fish in the Cyprinidae family commonly called rudds. The name “rudd” without any further qualifiers is used for particular species, especially the common rudd (Scardinius erythrophthalmus), a cyprinid fish native to Europe and middle Asia, with the areal from Western Europe to the Caspian and Aral Sea basins. A member of the minnow family, the fish prefer mainly in still or slowly moving, nutrient-rich and well vegetated waters. The genera comprises 10 species (S.erythrophthalmus, S. hesperedicus, S. knezevici, S. plotizza, S. dergle, S. acarnicus, S. elmaliensis, S. graecus, S. racovitzai and S. scardafa), more than half of them being rated on IUCN Red List from Near Threatened (NT) to Critically Endangered (CE). The classification of cyprinids has always been controversial, the number of recognized families varies depending on the author and the number of morphological traits considered and because the morphological traits are usually subjected to homoplasy, the systematics sometimes comes in contradiction with the molecular data. All these facts lead to the idea that the monophyletic groups described are probably misinterpreted. The aim of this study is to present the phylogenetic relationships within the Scardinius genera based on the COI gene molecular data. Total DNA was isolated for the species from Romania (S. erythrophthalmus and S. racovitzai) using different protocols according to the sample type. COI gene amplification was performed using the FISH F1 and FISH R1 primers. The amplicons were verified using gel electrophoresis and sequenced using CEQ 8000 Genetic Analysis System (Beckman Coulter). The GenBank sequences for Scardinius genera species COI gene dataset and Carassius carassius as outgroup were used. The sequences were aligned using ClustalW method from MEGA 7 software and the phylogenetic trees were constructed using BEAST v1.8 (Bayesian Evolutionary Analysis Sampling Trees). Within the Scardinius group, our analyses support most of the recognized species, indicating that S. erythrophthalmus species is not clustered in a monophyletic clade, appearing to be paraphyletic.