I have screened a λ-human recombinant DNA library using a purified human tRNA(Ser) and identified 7 clones which carry tRNA genes homologous to this tRNA. Three of the seven clones carry one identical Eco RI fragment which contains one tRNA(Ser) gene plus one other tRNA gene. Sequence analysis of the tRNA(Ser) gene from one of these three clones demonstrated that the tRNA(Ser) made from this human gene sequence differed at the 5' position of the anticodon from a previously sequenced homologous mammalian tRNA(Ser).