The spreading of epithelial sheets plays a pivotal role in normal embryonic morphogenesis but the cellular and molecular mechanisms underlying these processes are not very well understood. One way of directly examining epithelial spreading in the embryo is to excise a piece of tissue and follow the epithelial wound healing process. In this paper we report our studies of the healing of a simple excisional lesion to the E12.5 rat embryo hindlimb. The wounded, living embryo is cultured in a roller bottle and under such conditions the lesion is completely re-epithelised by 24 h. We find that epidermal cells specifically at the margin of the wound rapidly (within 15 min of wounding) and transiently express the nuclear transcription factor c-fos. This induction occurs whether or not serum is included in the culture medium. We speculate that local induction of c-fos at the wound site may play a role in regulating transcription of genes involved in the healing process.