Two types of self-assembled Fe nanowires (NWs) were grown by molecular beam epitaxy on ZnS(1 0 0) surface under high growth/annealing temperature. The type-A Fe NWs orient along the ZnS [1 1 0] direction with irregular shape, while the type-B Fe NWs orient along either the ZnS [1 8 0] or the [8 1 0] direction with seemingly straight shape. Detailed high-resolution transmission electron microscopy and selected area electron diffraction studies reveal that both types were single-crystalline with their elongated axis along the < 1 0 0 > direction family possibly due to the fact that the easy axis of Fe is along this direction. We have proposed a mean-field model to explain the slight misalignment of the type-B Fe NWs. The I-V characteristic of a single type-B Fe NW measured at room temperature displays a straight line nature corresponding to a resistivity of about 2.3 x 10(-7) Omega M, (c) 2008 Elsevier B.V. All rights reserved.