Gene therapy emerged as a promising novel treatment for undruggable diseases. Over the past few years, RNA therapy has emerged as a pivotal subset of gene therapy, with the development of the RNA technology. Here, we summarized the cutting edge investigations of RNA therapy, with a focus on its applications in treating various diseases, the results from clinical trials, and its future prospects. RNA therapy enables the precise regulation of dysfunction or disorder genes. Given the relatively straightforward design and preparation processes of the RNA-based medicines, they can be swiftly developed into novel therapies for diverse diseases. Moreover, RNA molecules offer new avenues for treating complex diseases and are poised to play a crucial role in the realization of precision medicine in the future.