Mouse rdh6 encodes cis-retinoid/androgen dehydrogenase type 1 (CRAD1), a short-chain dehydrogenase, which recognizes as substrates 9-cis-retinol, 11-cis-retinol, 5 alpha-androstan-3 alpha,17 beta-diol and 5 alpha-androstan-3 alpha-ol-17-one, and is expressed most intensely in liver and kidney. The present study reports the genomic organization, chromosomal localization and promoter region sequence of rdh6. Rdh6 spans more than 38 kb and consists of four exons ranging from 164 to 2200 bp, and three introns ranging from 550 bp to greater than 18 kb. The gene localizes to the distal end of mouse chromosome 10, 72.5 cM from the centromere, and colocalizes with mouse rdh7, which encodes CRAD2. This corresponds to the locus of human rdh5 on human chromosome 12. Primer extension assays indicate two major transcription start sites in liver and one in kidney. The approximately 2000 kb sequenced of the 5'-flanking region contains multiple potential transcription factor binding sites, including sites for AP-1, C/EBP beta, GATA, c-Rel, ER, ROR alpha, SREBP, and CREB.