Wound healing is a dynamic and complex process of tissue repair that involves a number of cellular and molecular events. It proceeds from inflammatory response to reepithelialization and finally to formation of a permanent scar. Alginate is a polymer of guluronic and mannuronic acid that is used as a scaffolding material in biomedical applications. For the purpose of studying wound healing, full-thickness skin defects were produced on the dorsal area in rats. We measured the relative sizes of the wounds on days 3, 5, 7, 14, and 28. The wound sizes were decreased in the alginate-treated group compared with the control group and the vaseline-treated group. The expressions of transforming growth factor-beta1, fibronectin, and vascular endothelial growth factor were significantly decreased in the alginate-treated group compared with the control group, while the expression of collagen-I was increased in the alginate-treated group, as indicated by Western blotting and immunohistochemical staining. These data suggest that alginate has significant wound healing promoting activity. The results from the present study indicate that the effect of alginate on wound healing may involve biological mechanisms associated with the expression of transforming growth factor-beta1, fibronectin, vascular endothelial growth factor, and collagen-I.