It is well accepted that ribonucleic acid, or RNA, is a central molecule of life that is actively involved in regulation and guidance of various essential cellular processes. This unique biological role makes RNA an important material for broad biomedical applications. RNA nanotechnology is a relatively new field of research that takes advantage of natural functional versatility of RNA as well as its ability to fold into complex three-dimensional structures. By learning from nature, RNA molecules can be rationally designed to self-assemble in defined architectures with desired physicochemical properties and biological activities for their further use in drug delivery, immunotherapies, biosensing, gene editing, material organization and other applications.