In Central Africa, copper ore occurs in only a few locations and copper appears to have been a scarce commodity in the past contrary to iron, which is attested more widely and earlier in the sub-Saharan archaeological record. This paper presents the first detailed characterization of an early copper-working region in Central Africa. Located along the southern border of the Republic of the Congo, the Niari Basin has revealed several copper production sites ranging from the 13th to the 19th century CE. The evidence, specifically in the Mindouli, Mfouati and Boko-Songho areas, includes various production remains as well as different types of copper ingots and artefacts. In the context of a broader copper technology study, the chemical and lead isotope characteristics of the ore deposits in this region are presented. The results of the chemical and lead isotope analyses of copper objects and production remains from archaeological sites are then interpreted against this geological background data, with an emphasis on copper provenance features. Combining these results with archaeological and historical evidence for regional metallurgical activity, new and significant insights are given on the production of copper in the Niari Basin, emphasizing the potential of this research for forthcoming work on copper use and trade in a wider Central African context.