One of the most effective strategies for bacterial disease management and prevention in aquaculture is the appropriate use of antimicrobials. Antibiotic misuse, on the other hand, may result in antimicrobial resistance (AMR) and the spread of antibacterial resistance genes (ARGs). ARGs are extrachromosomal DNA molecules that can be transferred by mobile genetic elements such as conjugative plasmids. Plasmids were extracted using a commercial kit from Lactococcus garvieae and L. petauri strains isolated from rainbow trout farms in Turkey, Greece, Italy, and Spain (20 strains from each country). Plasmids were screened for the presence of ARGs associated with tetracycline (tetA, tetB, tetC, tetG), phenicol (floR), beta-lactamase (blaTEM, blaSHV, blaOXA), quinolones oxalinic acid (gnrA, gyrA), macrolides (ermA, ermB, ermC), and streptomycin (strB). ARGs in plasmids were found in Italian strains but not in Spanish ones. Overall, tetG (30%) was the most common gene among all examined resistance genes, followed by gyrA (7.5%), strB (6.25%), blaSHV (5%), and tetB (3.75). The tetG resistance gene was found in all strains except the Spanish ones. This study suggests that tetracycline resistance is likely widespread in the Mediterranean region. In addition, irrational antibiotic usage may result in prolonged treatments and an increase in L. garvieae or L. petauri-related mortality. ARGs carried on plasmids may have a significant role in the transmission of antimicrobial resistance and the evolution of antibacterial resistance genes in rainbow trout farms in the Mediterranean region. Acknowledgment. This work study was supported by the Scientific and Technological Research Council of Turkey (grant number 119N446) as part of the PRIMA project. Keywords: Rainbow trout, L. garvieae, L. petauri, Plasmid, Antimicrobial resistance genes.