In the present study, fecal samples obtained from kelp gulls (Larus dominicanus), brown-hooded gulls (Larus maculipennis), and Olrog's gulls (Larus atlanticus) on the coast of the District of Pinamar, and grey-hooded gulls (Larus cirrocephalus) on the coast of the Lagoon Salada Grande and surrounding wetlands, General Madariaga, Buenos Aires Province, Argentina, were tested for evidence of avian influenza virus over a period of 3 yr. This surveillance in free-living wild birds in the Buenos Aires Province started in October 2008. Additional samples, which included cloacal swabs, tracheal swabs, or pooled organs, were obtained from sick or dead gulls that arrived at the Fundaci6n Ecol6gica Pinamar or were provided by the Direcci6n de Seguridad en Playas, Municipalidad de Pinamar. Samples were pooled according to date, species, and area. Pooled samples were inoculated in 9- to 11-day-old eggs, and after 5 days, allantoic fluids were tested for evidence of hemagglutination. None of the samples was positive for avian influenza viruses.