RNA-binding proteins play crucial roles in many biological processes, such as transcription, pre-mRNA splicing, nuclear-cytoplasmic transport of RNA, and translation of mRNA. Specific RNA-protein interactions are key to the correct assembly of ribonucleoprotein complexes and their biological functions. To date, more than 100 unique RNA-protein crystals have been prepared and there are more than 300 entries of RNA-protein complex structures in the Protein Data Bank. This chapter focuses on methods of RNA-protein complex crystallization discussed in six sections: determination of protein-binding sites in RNA, preparation of RNA, preparation of protein, annealing of RNA, reconstitution of RNA-protein complex, and searching crystallization conditions.