Electron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional structures of helical or zigzagged GaN, ZnGa2O4, and Zn2SnO4 nanowires. The GaN nanowires adopt a helical structure that consists of six equivalent < 0 (1) over bar 11 > growth directions with the axial [0001] direction. We also confirmed that the ZnGa2O4 nanosprings have four equivalent < 011 > growth directions with the [001] axial direction. The zigzagged Zn2SnO4 nanowires consisted of linked rhombohedrons having the side edges matched to the < 110 > direction and the [111] axial direction.