Resumen. Se informa del hallazgo de dos cetaceos fosiles, de la familia Balaenopteridae, encontrados in situ, casi completos y Articulados, en los alrededores de una quebrada tributaria del estero El Culebron, ciudad de Coquimbo, IV Region, Chile. Provienen de sedimentos marinos, semiconsolidados, de probable edad pliocena, pertenecientes a la Formacion Coquimbo. Abstract. This is a preliminary report of the in situ finding of two almost complete and articulated fossil Cetacea of the Balaenopteridae family, near a tributary gulch of El Culebron brook, in the city of Coquimbo, Chile. These vertebrates were found in semi-consolidated, marine sediments of the Coquimbo Formation, probably Pliocene in age.