Knowledge of the geographical distribution of the birds in the Colombian Caribbean is still meager. Coastal wetlands are among the less studied environments in the area and one of the most important for their high bird richness. Since 1998, inventories and monitoring of the bird populations of the lower part of the Sinú river have been made. Until July 2005, 296 bird species have been recorded for the area, 41 of which are new for this part of the Caribbean; in addition, new wintering localities were noted for eight migratory species. Breeding records were obtained for 98 species. Three species are threatened at some level and six have a restricted geographic distribution. New records for the area are explained in terms of the limited previous knowledge of the region’s avifauna.