The aim of this study was to examine the phenotypic susceptibility to antibiotics of gram-negative bacteria isolated from six stations under different anthropogenic influence in central Adriatic (Kaštela Bay, Kaštel Sućurac, Jadro, Split Channel, Vranjic and Stončica-Vis). The level of fecal contamination at the stations and the frequency of resistance to five antibiotics (cefotaxime, azithromycin, tetracycline, gentamicin, and sulfamethoxazole) were determined. The phenotypic susceptibility to 17 antibiotics for 93 isolates, classified into 9 families and 32 bacterial species, was determined by the disk diffusion method on Mueller-Hinton agar. The highest number of isolates was resistant to cefoxitin (74,19 %) and cefotaxime (63.44 %), and the lowest to gentamicin (8,60 %), ciprofloxacin and colistin (3,23 %). The frequency of resistance at stations is due to the composition of bacterial populations, among which species with intrinsic antibiotic resistance predominate. The results also indicate an association between the degree of fecal contamination and the resistance rate, especially for cefotaxime and tetracycline at Jadro and Kaštel Sućurac stations. Further research is needed on marine ecosystems that are under anthropogenic influence to better understand the overall spread of bacterial resistance to antibiotics and reduce the risk to human health.