RNA interference (RNAi) has emerged as a useful tool for the functional analysis of insect genes and the effective management of insect pests. However, the application of naked double-stranded RNA (dsRNA) can be ineffective in eliciting an efficient RNAi response in some insect species. The main reason for the failed or weak induction of RNAi is the low stability and delivery efficiency of naked dsRNA, thus a reliable dsRNA delivery method is needed. To this end, nanomaterials have been developed as effective carriers for RNAi delivery. In this chapter, we discuss the main factors constraining the RNAi efficiency in insects, illustrate the stability, cellular uptake and endosomal escape of the nanoparticle-delivered dsRNA, and finally summarize the recent progress and successful applications of nanoparticle-mediated RNAi in both basic research and pest management.