We study a single isolated Ag-Au nanowire with a nanofocused X-ray beam combining coherent diffraction methods in both forward scattering and diffraction geometries. X-ray scattering tomography measurements in forward geometry reveal a core-shell structure and allow determining the external size and shape of the nano wire. Bragg geometry measurements reveal the internal structure of the nanowire, notably the presence of stacking-faults in the nanowire. (C) 2016 Elsevier B.V. All rights reserved.