Cuyuni-Mazaruni is a region of Guyana. Its capital is Bartica, with villages including Issano, Kartabo, Kamarang, and Imbaimadai. It borders 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 borders the Brazilian state of Roraima to the south. It covers an area of 47,213 km².