We have determined the sequence of a 2784 bp rat genomic fragment originating from the 5' region of the gene coding for intestinal lactase-phlorizin hydrolase. The fragment overlaps the gene exon 1, part of the intron 1 and the 5'-upstream segment including a TATA-like box. Over 155 bp, the upstream segment shows 72% similarity with the corresponding sequence in human. Far upstream, the rat sequence exhibits a Calcium Responsive Element and putative binding sites for AP2, C/EBP, and CTF/NF. The intron contains a T-rich sequence that may cause DNA helix distortion.