RNA silencing is a rapidly expanding research field, not only because it is a fundamental biological issue but also because its application in the control of gene expression is highly promising. Post-transcriptional gene silencing in plants is a form of RNA silencing by which target RNA is degraded in a sequence-specific manner. Findings regarding the central role that double-stranded RNA plays in triggering RNA silencing have prompted the development of many modified methods for RNA silencing. These methods, in combination with the development of genomic resources, have provided rapid and efficient means by which to investigate gene function in a wide range of plant species. This review addresses the technical aspects of RNA silencing in plants by introducing the principles of several methods of RNA silencing, as well as the advantages and disadvantages of each method. © International Society of Differentiation 2004.