The gene of a 19 kDa cyclophilin of Tolypocladium niveum was isolated and sequenced. The open reading frame of 956 bp is interrupted by four introns of 76, 221, 58, and 61 bp size. 101 nucleotides upstream of the start codon ATG we found a putative promoter region containing a TATA and a CAAT box. The predicted amino acid sequence shows high identity to other cyclophilins, especially to the cyclophilin A family members of eucaryotic and procaryotic origin. Similar to the case of N. crassa we found a segment of 13 additional amino acid residues near the N-terminus which is not present in the other cyclophilins.