The petroleum sector is characterized by substantial rents when discovered and developed. However, such rents are inherently volatile and finite. The effects of these returns to the economy especially for the emerging markets depend on how well such revenues are collected and managed. The purpose of this brief is to examine the effectiveness of the current fiscal regime and its contractual implications. The investor and the government may have different objectives in the development of gas fields. With the current fiscal regime, a prospective investor can satisfy the objective of obtaining substantial profits from gas exploitation with an internal rate of return above the market discount rate of 10%. With proper tax administration, the government is able to maintain the current tax rates at the same time encourage exploration and development of fields which are commercially viable before and after-tax. By analysing the 2013 Model Production Sharing Agreement the author shows that with varying gas prices and costs of investments the current rent collecting system is progressive. Amidst the declining oil prices in the world market, a debate has emerged whether the Tanzanian fiscal regime is too tight or not and how it may affect Investments in the sector.