This chapter represents a revision and up- date of the bird species recorded in the state of Sonora, Mexico. The revision included published records of 89 papers and reports, 16,008 specimens deposited in zoological museums, and more than two hundred seventy-eight thousand field observations and banding records from the authors. A database with more than three hundred twelve thousand records was compiled incorporating information from 1849 to 2008. The avifauna of Sonora includes 556 species belonging to 73 families and 20 orders, with 227 all-year residents, 46 summer residents, 233 long-distance migrants, and 50 partial migrants. Museum specimens not considered previously and new data added 31 species to the number reported by Russell and Monson in 1998, and allowed us to evaluate the status of other species for the state. Twenty-eight of the species are of concern at the global level according to the Red list of Threatened Species of the IUCN, 290 are listed in the Neotropical Migratory Bird Conservation Act in the United States, and 66 are included in Norma Oficial Mexicana NOM-059- ECOL-2001.