As part of a survey of marine birds in the Southwest Atlantic, a field trip was made to Golfo San Matías, on the coast of southern Argentina, to accomplish a first evaluation of seabirds associated with the Argentine squid Illex argentinus fishery by jiggers. Between 7–21 July 2003, 20 species of seabirds belonging to 6 families were observed. On July 21, at 41°17'S, 64°36'W, a Trinidade Petrel (Pterodroma arminjoniana) was observed along with 100 Thalassarche melanophris, 200 Larus dominicanus, 10 Macronectes giganteus, 20 Oceanites oceanicus and 10 Procellaria aequinoctialis. We discuss some aspects of field identification, taxonomy and conservation. The data and circumstances of our record allows us to speculate that it is possible that vagrant birds, or maybe sub-observed regular visitors, may be associated with the squid fishery on the Argentine continental shelf.