The effects of the topical antiseptic agents mercurochrome and silver nitrate and of sodium hyaluronate on the process of wound healing were assessed by macroscopic examination, light microscopy histology, electron microscopy and scanning electron microscopy of wounds made by cutting or by abrasion of the skin of rats. It was found that wounds treated with hyaluronic acid underwent longer periods of inflammation (proportional to the presence of mastocytes) and greater amounts of collagen deposition than wounds that were either untreated controls or treated with silver nitrate or mercurochrome, but this did not impede the formation in the early stages of healing of bridges of fibrin between the edges of the wounds.