As one of its efforts to scale up promotional programs for attracting investments in the development and utilization of Tanzania’s mineral resources, the Geological Survey of Tanzania has made major review of the previously existing Mineral Occurrence Map of Tanzania through verification of location of known occurrences of minerals coupled with thorough evaluation and description of geological processes which account for the forͲ mation of these resources as well as their mineral association. The upgrading of this information went hand in hand with the inclusion of the similar data and information for the recently discovered occurrences of some commodities. As a result of these recent reviews and upgrading of information, a new GISͲbased MineroͲ genic Map of Tanzania at a scale of 1:1,500,000 has been developed and published in 2015. The content of this booklet serves as explanatory notes for this newly published map. The aforeͲstated review of information of mineral occurrences and the subsequent publication of the new map was carried out under the implementation of the Sustainable Management of Mineral Resources Project (2009 to 2015), a project that was funded by the World Bank and the Government of Tanzania. Beak Consultants GmbH of Germany was engaged as the consultant for conducting the review and publishing the map and its explanatory notes. Apart from publishing this map using conventional methods (hard and soft copies) the map and all its associated information and explanatory notes are posted in the newly developed web portal of the Geological Survey of Tanzania established in 2015 with address of www.gmisͲtanzania.com, a portal that serves as a platform for online viewing and searching of geoͲdata and information available at the Geological Survey of Tanzania. The Geological Survey of Tanzania is of the opinion that this new map and its explanatory notes, particularly the one placed on the web portal, will facilitate quick and easy disseminaͲ tion of information on the raw materials in the country to potential investors, stakeholders and the general public across the world. This will also allow onͲline quick querying of available geoͲdata related to the extractive industry in Tanzania and hence attracting more investment to the country therefore paving the way to an accelerated economic growth of the country. The Geological Survey of Tanzania encourages all stakeholders to make a good use of the newly developed Minerogenic Map of Tanzania and its explanatory notes and it is committed to providing additional explanations, data and information whenever required in order to ensure thorough understanding of the countryͲwide existing potentials of the minerals to all potential investors, stakeholders and the general public. Let us join hands and efforts to develop the raw materials for the benefit of Tanzania, her people, the investors and the world community at large in line with the “Win – Win” spirit.