The use of Caenorhabditis elegans as a model system for understanding animal development and human disease has long been recognized as an efficient tool of discovery. Recent developments, particularly in our understanding of RNA-mediated interference and its ability to modify gene activity, have facilitated the use of C. elegans in determining gene function via high-throughput analysis. These new strategies have provided a framework that allows investigators to analyse gene function globally at the genomic level and will likely become a prototypic model for biological analysis in the post-genome era.