Abstract: In this study, radial ZnO-core/ZnS-shell nanowire heterostructures were deposited at atmospheric pressure by atomic layer deposition (ALD) using diethylzinc (DEZn), nitrous oxide (N2O) and ditert-butylsulfide (DTBS) precursors. The structural and optical properties of radial ZnO-core/ZnS-shell nanowire heterostructures were characterized using θ-2θX-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and photoluminescence spectroscopy (PL). It was found that both ZnO-core and ZnS-shell of the ALD-deposited radial ZnO-core/ZnS-shell nanowire heterostructure were wurtzite in nature based upon the results of HRTEM investigations. Moiré fringes were identified in the radial ZnO-core/ZnS-shell nanowire structure with an observed period being in good agreement with the lattice mismatch between ZnO-core and ZnS-shell of the pseudomorphic ZnO-core/ZnS-shell nanowire heterostructure. Neutral donor excitonic emissions (D°X) along with related longitudinal optical phonon (LO) replicas of ZnO cores were observed in the 10 K PL of the ALD-deposited radial ZnO-core/ZnS-shell nanowire heterostructures.