One hundred and two samples of mussels (Mytilus galloprovincialis), harvested from approved shellfish coastal water in northern Greece, were screened for the presence and antimicrobial resistance of Listeria monocytogenes. Listeria spp. were isolated according to International Organization for Standardization method 11290-1: 1996/FDAM 1: 2004(E) and identified using a multiplex polymerase chain reaction (PCR) system. The serovar identity of L. monocytogenes isolates was also determined with a multiplex PCR assay. The antimicrobial profile of the isolates was determined by the disk diffusion method. Listeria spp. were present in 8 of 102 samples tested (8%) and only 1 (1%) yielded L. monocytogenes. The isolate identified as L. monocytogenes was defined as serogroup I and found to be resistant to nalidixic acid and streptomycin. In conclusion, this study demonstrated that L. monocytogenes is not commonly found in mussels harvested in the North Aegean Sea, whereas there is a higher possibility of mussels' contamination with other Listeria species.