From June 1988 to July 1992, non-continuous samples of two species of cartilaginous fish of the family Triakidae were taken in the National Natural Park Gorgona. Stomach contents of 139 individuals of Mustelus lunulatus and 51 individuals of M. henlei were analyzed. These species predate on crustaceans (93,06%), mainly Portunus iridiscens, Squilla panamensis and Hipoconcha panamensis, secondly on mollusks of the family Loliginidae (4,32%) and fishes (2,28%) in a smaller proportion; the remaining 0,34% corresponded to digested material. Nematodes and isopods were found in the stomach contents of these fishes, but we considered them as accidentals and were not included in the analysis.