Technical Abstract: Virus-induced gene silencing (VIGS) is an important tool that permits the rapid knockdown of plant gene expression to determine their function. To initiate VIGS, a transcript of a viral construct carrying a fragment of a plant gene is used to infect a plant. Viral infection triggers a conserved, RNA-based, plant antiviral defense pathway that results in sequence-specific degradation of the entire viral RNA sequence, including the inserted plant gene fragment. The plant gene mRNA from which the viral insert was derived also is targeted for degradation, resulting in host gene silencing. Unfortunately, only a few combinations of viruses and hosts result in effective VIGS for functional genomics applications. Very recently, useful VIGS tools have become available for use in the Poaceae. Here the properties of the existing VIGS tools for grasses are described and their uses and limitations are discussed.