In metazoans, fertilization initiates vast remodeling of the embryonic proteome and transcriptome. This is accomplished via complex post-transcriptional regulation of maternal and zygotic RNA. RNA-binding proteins (RBPs) are one of the major mediators of embryonic post-transcriptional RNA regulation. Thus, elucidation of the molecular mechanisms by which maternal and zygotic transcripts change their translational capacities and expression levels requires thorough and precise determination of the targets and binding sites of individual RBPs in embryonic transcriptomes. Here, I provide a detailed protocol for the UV crosslinking-based method, named iCLIP, to study RBP functions during early zebrafish embryogenesis.