Large potentials for CO2 storage were demonstrated in previous studies in Brazil. This study aims to estimate the CO2 storage capacity in the Campos Basin's oil fields, Southeast Brazil, in order to provide refined values to support CCS planning in the country. The results, based on field/reservoir level data show that there is a large potential for CO2 storage (ca. 950Mt) in the 17 assessed oil fields in the basin, and 75% of this storage capacity is found in sandstone reservoirs.