Predation strategies of Trophon geversianus (Trophonidae) on four bivalve species: Mytilus chilensis, Aulacomya atra, Hiatella solida and Tawera gayi, from the fuegian region were analyzed. Data were obtained by three methods: analysis of bored shells transported on modern beachs, study of predation under laboratory conditions, and observation of predation on populations in the field. We conclude that (1) not all muricid holes are cylindrical; (2) there is variation among prey species in the shapes of holes and in the sites of drilling; and (3) predation intensity is low to moderate.