Gaidropsarus guttatus is a nocturnal predator that dwells in rocky bottoms of Macaronesian coastal areas. There are no studies as yet on the feeding ecology of this species. This paper describes the feeding habits of this quite unknown species, based on a sample from Faial Island, Azores, Portugal. This sample is composed of 82 specimens collected between August 1997 and April 1999, both in intertidal pools and sub-tidal shallow waters (max. depth 10 m). 95% of sampled stomachs contained food items totaling 303 preys from 11 different taxa. Most important items were decapoda (45%), from which Pachygrapsus marmoratus (24%) showed to be clearly a dominant prey. Teleost fish represented 17% of all prey items. The significant presence of benthonic species and algae in their stomach contents do suggest that G. guttatus is an opportunistic suction feeder predator.