In this work we fabricated diamond replicas with silicon molds. The samples analyzed were silicon treated by diamond powder creating nanostructures on it. The diamond films were deposited by CVD technique. Then the silicon substrates were wet-etched, obtaining the diamond replica. The fidelity of nanometric and micrometric structures of the diamond replicas were analyzed by AFM technique. The surface roughness is a significant parameter to determine the fidelity of the replicas. We verified that the fidelity of diamond replicas on silicon substrate depends on the substrate preparation.