The Caenorhabditis elegans gene unc-5 and it's vertebrate homologues are Netrin receptors. In this study, I report the cloning of three mouse Unc5 family members, namely, Unc5h1, Unc5h2 and Unc5h4. Furthermore, a comparative expression analysis is presented with Unc5h3, deleted in colorectal cancer and Netrin-1. Transcript distribution is studied during early eye development, mammary bud formation, vascularisation, and limb development. The most widely expressed Unc5 family member is Unc5h2 and it's mRNA is observed during early blood vessel formation, in the semicircular canal and in a dorsal to ventral gradient in the retina. Unc5h1 expression is restricted to the central nervous system, whereas, sites of Unc5h4 expression are in the developing limb and mammary gland.