SUMMARYHomografts of mouse skin in which cellular viability had been destroyed by repeated freezing and thawing or by treatment with cyanide but in which major structural changes had not occurred were accepted by the host without evidence of immune reaction, either by histologic criteria or by challenge with second-set viable grafts. Treated homografts evolved like similarly treated isografts. With adequate protection these dermal homografts persisted for long periods without necrosis, undergoing eventual resorption and replacement by scar tissue, rather than being revascularized and repopulated by host connective tissue cells. The acellular dermal homografts supported growth of isologous epithelium derived from grafts or from marginal ingrowth. These findings question the concept of cellular repopulation of non-viable autologous or homologous connective tissue grafts.