The amino acid sequence of rat ribosomal protein S24 was deduced from the sequence of nucleotides in a recombinant cDNA. S24 contains 133 amino acids and has a molecular mass of 15,413. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 12-16 copies of the S24 gene. The mRNA for the protein is about 600 nucleotides in length. Rat S24 is homologous to Xenopus laevis S19 and related to Halobacterium morismortui ribosomal protein S15.