A total of 71 loggerhead turtles (Caretta caretta) stranded along the coasts of Sicily (Southern Italy) were examined for nonâdioxine like polychlorinated biphenyl (NDL-PCB) levels in muscle and adipose tissue by a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) method. The results revealed 6 high-indicator congener (â6PCBIND) levels in 45% of the loggerhead turtles examined, with mean values of 980.39 Â± 2508.39 ng/g wet weight in adipose tissue and 102.53 Â± 238.58 ng/g wet weight in muscle tissue. The hexachloro and heptachloro PCB congeners were the most abundant in both the sample types. The highest NDL-PCB levels were reached in an adipose tissue sample of a loggerhead turtle of 80 kg stranded along the coasts of Termini Imerese (14 183.85 ng/g wet wt). No significant correlation was found between modified Fulton's K values of the loggerhead turtles and PCB contents (S = 47 151, p > 0.05). Furthermore, no significant differences were found between sexes (W = 365, p > 0.05). The PCB levels found in the present study were much higher than those found in the literature. The present study is the first report on the existence of NDL-PCBs in loggerhead turtles stranded in Sicilian coasts confirming C. caretta as a valuable indicator of contaminant exposure in the marine environment because of their specific biological and ecological characteristics. Environ Toxicol Chem 2017;36:2997â3002. Â© 2017 SETAC.