The Pará-Maranhão Basin is an Equatorial Brazilian basin that extends over an area of 48,000 km² in the offshore portion of Pará and Maranhão states. Its geological limits can be summarized as the Barreirinhas Basin (to the Southeast); the Foz do Amazonas Basin (to the Northwest); the shallow basement and Ilha de Santana Platform (to the South). Such limits are arbitrary, since there are no significant tectonic features in order to compartmentalize the mentioned Equatorial basins. The basin is a high-risk frontier of exploration for oil and gas resources. Nevertheless, the presence of at least four different active petroleum systems motivate the oil industry to go further in the investigation for oil and gas resources in this area and, once again, critically evaluate new opportunities. In order to evaluate the exploratory potential of Pará-Maranhão Basin, BPS have developed a study to rank the best areas for petroleum exploration based on the integration of different approaches and exploration tools like seismic interpretation and mapping, high-resolution geochemistry, reservoir petrophysics, tectonic, structural and stratigraphic framework reconstruction and petroleum system quantitative modeling.