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The Bom Jardim de Goiás copper deposit is a remarkable example of a deposit formed in a Neoproterozoic juvenile arc in the South American Platform during the assembly of Gondwana. The deposit is inserted in the western margin of the Arenópolis Magmatic Arc, in the Tocantins Province. The host rocks comprise a volcanosedimentary sequence of intermediate to acid composition interpreted as crystal and ash tuffs. The tuffs represent calc-alkaline volcanism of rhyodacitic to dacitic composition, with lithogeochemical and biotite chemistry characteristic of magmas from intra-oceanic arcs. The tuffs are commonly cut by veins and veinlets with no preferential orientation and show ε Nd(t) values between +3.5 and +7.4 and T DM model ages ranging from 0.8 to 1.1 Ga, consistent with juvenile magmas generated in magmatic arc settings. Intrusive bodies in the volcanosedimentary sequence are represented by hornblende-biotite monzogranite, interpreted as Serra Negra Granite, and biotite syenogranite defined as Macacos Granite. The granites have geochemical characteristics of type I calcalkaline granites, generated in a post-collision setting. Tholeiitic basalts intercalated with tuffs, interpreted as flows, show geochemical affinity with volcanic arc basalts, whereas the dikes that crosscut the granites have compositions characteristic of intra-plate tholeiitic basalts. The petrological data of the host and country rocks of the Bom Jardim de Goiás area reveal an important production of calc-alkaline magma in a magmatic arc setting in western Goiás around 750 Ma, genetically related to copper mineralization, and the generation of a non-mineralized post-collisional magmatism at 540 Ma.