Three new human nuclear tRNA(Leu) genes have been isolated and sequenced using the PCR technique. Two of them represent genes containing a CAA anticodon and both contain introns of 22 nucleotides in length but differing in sequence. Intron-containing prolongated anticodon stems can be folded into a secondary structure similar to that of yeast pre-tRNA(Leu). The evolutionary conserved secondary structure suggests the same role of intron sequences in the human and yeast pre-tRNA(Leu) maturation pathway.