The Castelo Intrusive Complex (CIC), located in the southern state of Espírito Santo, southeast-ern Brazil, is a pluton inserted in the context of post-collisional magmatism of the Araçuaí Orogeny, known as Supersuite G5, related to the extensional collapse during the Brasili-ano/Pan-African Orogeny. This work presents an integration of field, petrographic, lithogeo-chemical, and isotopic data, in addition to bringing new U-Pb ages for the CIC and a new geo-logical map. The CIC presents a great compositional variety, presenting rocks of monzogranitic, granodioritic, quartz-monzodioritic, and dioritic compositions that are inserted in the context of mixed magmas. The magma mixing process is generalized in the CIC through field, petro-graphic, lithogeochemical, and isotopic data, in addition to U-Pb data in the different units that attest to the cogeneticity between them. The delamination process promoted the fusion of the asthenospheric mantle. It promoted the anatexis of different portions of the crust, evident through the values of εHf and TDM ages, where later magmatic mechanisms of physical disper-sion (mingling) and chemical diffusion (mixing) favored hybridization and promoted the com-positional diversity of the CIC.