The North Fluminense region, which experienced periods of economic strength specially at state and national level throughout the 19th century and the first half of the 20th century with its economy based on sugarcane production, started to experience, as of the end of the 20 century a significant change in its productive configuration based on industrial activities and provision of services direct and indirectly linked to the oil industry, as well as the fact that five of its nine municipalities are major beneficiaries of royalties and special participations. This article aims to examine to what extent the production and extraction of oil and gas (O&G) has contributed to the economic growth of North Fluminense, and examine whether their economic behavior is analogous to that seen at state and national level, regarding the behavior of the industrial sector. It also seeks to identify the effects of the international crisis of 2009 on the regional economic behavior.