Large-area Zn2GeO4 nanorod arrays (1.5 x 5 cm) and long Zn2GeO4 nanowires (length up to 1 mm) have been controllably prepared at different areas on the substrate using a simple thermal evaporation method. The formation processes for these nanostructures were investigated carefully. The solid state reaction and vapor-solid process have been found to clearly contribute to the creation of the Zn2GeO4 nanorod arrays and long Zn2GeO4 nanowires, respectively. Photoluminescence (PL) characterization of these nanostructures showed that both the nanorod arrays and nanowires exhibited strong blue-white luminescence. Mn-doped Zn2GeO4 nanorod arrays have also been obtained by doping an appropriate amount of Mn2+ ions in the products. Zn2GeO4 nanostructures doped with Mn2+ exhibited bright green luminescence.