Antarctic and sub-Antarctic seabirds are widely distributed and have a large migratory movement, usually using the South Atlantic region as a resting and foraging area. The aim of this study is to quantify the mortality of Antarctic and subAntarctic seabirds along the Brazilian Southern Coast and compare this data between two periods with an interval of eleven years. The census was conducted between Balneario Pinhal and Mostardas, Rio Grande do Sul State. A total of 1183 carcasses were recorded in the two years of study: 1087 during the first year (1997-1998) and 96 in the second (2008-2009). 15 species were identified: Diomedeidae (n = 4) and Procellariidae (n = 11). The mortality of Antarctic and sub-Antarctic seabirds on the Southern Brazilian Coast can be a consequence of several factors: anthropogenic and climate phenomena. After eleven years, the significant decrease in the number of individuals indicate efficient mitigation measures contributing to a reduction in mortality of species of seabirds in the South coast of Brazil.