Cloning and sequencing of the genomic DNA of Fusarium moniliforme encoding ribonuclease F1 was successfully performed. The gene consists of three exons separated with approximately 50-bp long introns. The gene structure was compared with those of several homologous ribonucleases found in the sequence database. It was found that one interesting feature reported for the ribonuclease T1 gene of Aspergillus oryzae is conserved among three species of Aspergillus genus and F. moniliforme. The feature is that a very short exon encoding the presequence consisting of only five amino acid residues is connected to the next exon in phase 0.