The Cardinalfish, Epigonus crassicaudus, is a species of economic importance for the fishing activity that operates in south-central Chile. Despite this, little is known about their biology. Therefore, this work studied the feeding habits combining stomach contents and stable isotopes analyses. The results showed that the mesopelagic fishes (Myctophidae, Stomiidae) were the most important prey contributing an 80% in the Cardinalfish diet, following by the crustaceans (Sergestes arcticus) with 10%. No differences were detected among maturity stages. Furthermore, the stable isotopes result exhibited average values of delta N-15 17.12 +/- 1.1 and delta C-13 -17.51 +/- 0.7 delta C-13 values was proportional to the cardinalfish size, which larger specimens inhabit deeper (demersal) than those with small size. According with these results the Cardinalfish is positioned as a secondary consumer.