Abstract The Campos Basin, located offshore from Rio de Janeiro in southeastern Brazil, is the most prolific petroleum-bearing basin in Brazil. To date, Petrobrás has discovered more than 70 hydrocarbon accumulations in the basin, including seven giant oil fields in deep water. The Campos Basin accounts for more than 80% of the total exploitable Brazilian reserves and 75% of total oil production. The Barremian calcareous shales from the Lagoa Feia Formation are the source rocks of all the oil in the basin. Accumulations occur in a variety of siliciclastic and carbonate reservoirs, ranging from Barremian to Miocene in age. Upper Cretaceous–Tertiary turbidities contain most of the oil, but Neocomian basalts also contain commercial accumulations. Peak oil generation occurred during late Miocene time, and the most important migration pathways are through salt windows and along listric faults.