RNA molecules interact with proteins to drive many cellular activities, including post-transcriptional processing of RNA, regulation of translation, and transport of RNA to name but a few. These ribonucleoprotein complexes are isolated by coimmunoprecipitation (co-IP), where a protein-specific antibody is used to purify the protein of choice and its associated complex members. Analysis of RNA-Protein Complexes by RNA Coimmunoprecipitation and RT-PCR Analysis from Caenorhabditis elegans gives step-by-step instructions for RNA co-IP from C. elegans whole-worm extracts. The protocol, from Christian Eckmann and colleagues at the Max Planck Institute of Molecular Cell Biology and Genetics, starts with the large-scale growth of worms and describes the preparation of whole-worm extracts, RNA co-IP, isolation of the purified RNA, and identification of specific genes through RT-PCR. As one of our featured articles for October, the protocol is freely available to subscribers and non-subscribers alike. Eckmann and colleagues have also contributed an accompanying article describing Analysis of In Vivo Protein Complexes by Coimmunoprecipitation from Caenorhabditis elegans.