We analyzed the diet composition of 49 loggerhead sea turtles found dead in the northern Adriatic Sea (Croatia and Slovenia), in the period between 2001 and 2004. Curved carapace length of loggerheads ranged from 25.0 to 79.2 cm (mean: 42.2 ± 11.6 cm). The anthropogenic debris was isolated from the digestive tract contents. Debris samples were later air dried, weighted, measured and divided into groups. The anthropogenic debris was found in the digestive tract of 17 loggerheads (34.7%). Four types of debris were found: plastics, ropes, styrofoam and lines. Most of the ingested debris was transparent or white colored and was found in 64.7% of turtles. Plastic was the most frequent type of debris, recorded in 11 turtles (64.7%). The quantities of the debris found were very small, and the range of dry mass was between < 0.01 and 0.71 g, which indicates that the ingestion of anthropogenic debris is not the direct cause of death of the analyzed turtles. Considering relatively high frequency of occurrence and possible sublethal effects of debris ingestion, together with the opportunistic feeding nature of this species and the significance of the northern Adriatic as an important benthic feeding habitat, it is important to minimize the input of debris, especially plastic, into the Adriatic Sea. That is one of the prerequisites for the effective conservation of the population of loggerheads that inhabit the studied region.