Caenorhabditis elegans, a 1 mm long free-living nematode, is a traditional model animal for genetic investigations of various biological processes. Characteristic features that make C. elegans a powerful model of choice for eukaryotic genetic studies include its rapid life cycle, well-annotated genome, simple morphology, and transparency. Recently, genome editing technologies have been increasingly used in C. elegans, thereby facilitating their genetic analyses. Here, I introduce a protocol frequently used in C. elegans genome editing.