The gene for the sheep arginine vasopressin type 1a (V1a) receptor subtype was cloned from a genomic library. The deduced amino acid sequence shows characteristics of a G-protein coupled receptor and high sequence identity to human and rat V1a receptor sequences (81% and 73%, respectively). Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed a tissue distribution consistent with a type V1a receptor. The genomic DNA (7.1 kb) contains a 1586 bp intron between the putative 6th and 7th transmembrane domains.