Wound repair/regeneration is a complex process consisting of three stages: inflammation, tissue regrowth, and remodeling, which together involve the action of hundreds of genes. In order to i) identify and analyze the genes that are expressed at the inflammatory stage of repair (i.e., 24 h after injury) and ii) evaluate the molecular basis of fast-wound repair/regeneration in adult mammals, we examined the expression of 8734 sequence-verified genes in response to ear punch in a fast wound-repair/regeneration strain, MRL/MpJ-Fas^lpr mice, and a slow-wound-repair strain, C57BL/6J mice. Many differentially expressed genes can be assigned to wound-repairing pathways known to be active during the inflammatory phase, whereas others are involved in pathways not previously associated with wound repair. Many genes of unknown function (ESTs) exhibited a more than twofold increase in MRL/MpJ-Fas^lpr or C57BL/6J mice, suggesting that current understanding of the molecular events at the inflammatory stage of repair is still limited. A comparison of the differential expression profiles between MRL/MpJ-Fas^lpr and C57BL/6J mice suggests that fast-wound-repair in MRL/MpJ-Fas^lpr mice is mediated by a metabolic shift toward a low inflammatory response and an enhanced tissue repair.