The nmt1+ gene of the fission yeast Schizosaccharomyces pombe is subject to transcriptional repression mediated by thiamine. The promoter of nmt1+ has been used to construct a series of vectors that are now commonly used for the regulated expression of genes in S. pombe. In this report, we described ntf1+, a gene involved in regulating nmt1+ expression. The ntf1+ gene was cloned in a high copy suppressor screen that utilized a construct, nmt1:wee1+, in which expression of the mitotic inhibitor Wee1 tyrosine kinase was placed under the control of the nmt1 promoter. ntf1+ encodes a 706-amino acid protein that shares substantial homology with a family of Cys6 zinc finger-containing transcription factors typified by GAL4 from Saccharomyces cerevisiae. Increased gene dosage of ntf1+ greatly increases both the repressed and derepressed activity of the nmt1 promoter. Cells having a disrupted version of ntf1+ are viable thiamine prototrophs, but basal expression from the nmt1 promoter is greatly reduced. These data demonstrate that Ntf1 plays an important role in regulating nmt1 expression.