Several recent studies have highlighted how RNA interference has advanced aging-related research in Caenorhabditis elegans. Two new genome-wide RNAi-based screens together identified more than 100 new candidate longevity genes. RNAi has also greatly facilitated the functional validation of several large-scale gene expression profiling studies. Furthermore, RNAi is flexible and can be administered at different times throughout life; this feature has been exploited to analyze the temporal requirement of genes in life-span determination.