RNA interference (RNAi) has been widely used for genetic research in insects. Recently, RNAi via ingestion was considered as a potential tool for insect control. Several studies demonstrated that targeted insects can be effectively by the ingestion of RNAi-based insect resistant biotech crops with obvious commercial implications. In the meantime, the environmental risks should be carefully considered before the commercial use of RNAi-based crops. To set up an environmental risk assessment framework for RNAi-based biotech crops, the regulatory agencies and stakeholders as well as risk analysts need to be familiar with the science of RNAi and its application to plant biotechnology. Scientific questions need to be answered about unintended gene silencing (including non-target effects), off-target binding (off-target effects), target resistance, stability and persistence of small interference RNA (siRNA) in various ecosystems, uncertainties, etc. In comparison of information required in an application to a regulatory agency for a transgenic Bt crop, data collection for RNAi-based insect resistance biotech crops should include the molecular characterization and expression of dsRNA (i.e. nucleotide sequence, length, the concentration of dsRNA for an optimal silencing and the persistence of the silencing effect), the potential activity spectrum and the impacts on non-targets, the environmental persistence of small RNA molecules, the persistence of the silencing effect and therefore the efficiency of RNAi as an insect control technique. The accepted environmental risk assessment process will need to be adaptable for analysis of RNAi-based biotech crops, which could prompt the development and production. Filling the numerous knowledge gaps surrounding these risks will improve this predictability.