Arrays of GaN nanowires (NWs) and nanotubes (NTs) have been grown by metalorganic vapor phase epitaxy using a gold–nickel film as the catalyst. The simultaneous formation of both NTs and NWs in one process in the presence of various Au–Ni catalyst compositions is explained. It is established that NTs grow on solid catalyst particles, while NWs grow according to the classical vapor–liquid–solid mechanism. The optoelectronic properties of obtained NTs and NWs have been studied using photo- and cathodoluminescence techniques.