Zinc finger genes represent a large multigene family present in mammalian and other genomes. A subgroup of these genes contain a conserved motif, the KRAB domain, at the NH2-terminal region, which was recently shown to posses a potent transcriptional repression activity. For one such gene, ZNF45, we determined the complete coding sequence, along with the exon/intron arrangement and the splice junctions. Exon 2 codes exclusively for the KRAB-A element of 42 amino acids, and exon 4 contains the 19 zinc finger repeats. In addition, we generated an EST (expressed sequence tag) from the 3'-end of ZNF45 that we used for polymerase chain reaction screening of a P1-derived genomic library. We isolated a 65-kb clone that was used for localizing this gene on chromosome 19q13.2 by fluorescence in situ hybridization.