Both DNA and RNA can serve as powerful building blocks for bottom-up fabrication of nanostructures. A pioneering concept proposed by Ned Seeman 30 years ago has led to an explosion of knowledge in DNA nanotechnology. RNA can be manipulated with simplicity characteristic of DNA, while possessing noncanonical base-pairing, versatile function, and catalytic activity similar to proteins. However, standing in awe of the sensitivity of RNA to RNase degradation has made many scientists flinch away from RNA nanotechnology. Here we report the construction of stable RNA nanoparticles resistant to RNase digestion. The 2'-F (2'-fluoro) RNA retained its property for correct folding in dimer formation, appropriate structure in procapsid binding, and biological activity in gearing the phi29 nanomotor to package viral DNA and producing infectious viral particles. Our results demonstrate that it is practical to produce RNase-resistant, biologically active, and stable RNA for application in nanotechnology.