Post-transcriptional regulation of gene expression plays an important role in complex cellular processes. Just like transcription factors regulate gene expression through combinatorial binding to multiple, physically dispersed cis elements, mRNA binding proteins can regulate the translation of functionally related gene products by coordinately binding to subsets of mRNAs. The networks of mRNA binding proteins that facilitate this fine-tuning of gene expression are poorly understood. By combining genomic technologies with standard molecular biology tools, we have helped pioneer the development of high-throughput technologies for the global analysis of subsets of mRNAs bound to RNA-binding proteins. This technique is termed RIP-Chip and stands for RNA-Binding Protein Immunoprecipitation-Microarray (Chip) Profiling. This approach is also referred to as "ribonomic profiling" and has revealed valuable information about the workings of mRNP networks in the cell and the regulation of gene expression. In this chapter, we describe the latest advances that we have made in the RIP-CHIP technology.