Purified, isolated yeast tRNA Ser2 was used as a hybridization probe to estimate the number of tRNA Ser2 genes in the yeast genome. Molecular clones of several of the genes were obtained. Three examples were studied in detail with respect to their genomic organization, and DNA sequences were determined for them. There appear to be eleven tRNA Ser2 genes in the yeast genome. They are neither tandemly repeated, nor clustered with other tRNA genes. They contain no intervening sequences.