This volume of Methods in Enzymology aims to provide a reference for the diverse, powerful tools used to analyze RNA helicases. The contributions in this volume cover the broad scope of methods in the research on these enzymes. Several chapters describe quantitative biophysical and biochemical approaches to study molecular mechanisms and conformational changes of RNA helicases. Further chapters cover structural analysis, examination of co-factor effects on several representative examples, and the analysis of cellular functions of select enzymes. Two chapters outline approaches to the analysis of inhibitors that target RNA helicases.