This Selected Issues paper discusses the potential fiscal impact of a large-scale gas project and explores aspects of macro-fiscal management of the associated revenue flow. The chapter also provides background and context focusing on recent offshore natural gas discoveries. The paper also describes features of the current petroleum fiscal regime in Tanzania and will present tentative simulations of the fiscal impact of a potential gas project. A string of natural gas discoveries in Tanzania’s deep offshore waters have generated considerable expectations. The outlook for natural gas in Tanzania is positive, albeit still highly uncertain. If major revenues are obtained and put to fruitful use, they could have a transformational impact on the economy. At the same time, expectations need to be tempered by the remaining uncertainty about the eventual size of the gas resources; no company has yet made a final investment decision involving the deep offshore gas reserves. This uncertainty will hopefully diminish in the next few years.