This paper presents data on the diet of the musky octopus, Eledone moschata, caught with bottom-trawl nets in the northern Adriatic Sea from October 2001 to June 2003. A total of 1226 stomachs were examined, out of which 34.8% were empty. Several indices were used to describe the diet of the species. Crustaceans were found to be the most important prey category and their remains occurred in 65.0% of stomachs with food. Fish and cephalopods were present in 37.8% and 21.8% of stomachs, respectively. Differences in food composition between smaller and larger individuals were observed. In specimens with mantle lengths up to 80 mm crustaceans dominated, occurring in 79.4% of examined stomachs. Important prey categories of the larger specimens (>80 mm) were crustaceans, fish and cephalopods. No significant differences in the diet between males and females were found. Cannibalism occurred only occasionally and at larger sizes. Seasonal changes in the diet were observed, but seasonality did not seem to be a limiting factor in the feeding intensity of the species. Results indicate that the observed differences in the diet composition and feeding dynamics of the musky octopus are primarily due to the animals' changes in size.