High-aspect ratio beta-Ga2O3 nanorods consisting of prism-like crystals were formed using gallium oxyhydroxide and ammonia hydroxide via a hydrothermal synthesis followed by the subsequent calcination process. The formation of high-aspect ratio beta-Ga2O3 nanorods was attributed to the oriented attachment mechanism that was present during the hydrothermal synthesis. A field-effect transistor was fabricated using the high-aspect ratio beta-Ga2O3 nanorod, and it exhibited the typical charge transfer properties of an n-type semiconductor. This facile approach to forming high-aspect ratio nanorods without any surfactants or additives can broaden the science of beta-Ga2O3 and expedite the integration of one-dimensional beta-Ga2O3 into future electronics, sensors, and optoelectronics.