Cuyuni-Mazaruni (Region 7) is a region of Esequiban Guyana, a territory in dispute by Guyana and Venezuela, bordering the regions of Barima-Waini, Essequibo Islands-West Demerara and Pomeroon-Supenaam to the north, the region of Upper Demerara-Berbice to the east, the region of Potaro-Siparuni and Brazil to the south and Venezuela to the west.