To assess the efficacy of a topical 4% metronidazole solution in wound healing by secondary intention in rats.We made circular wounds two inches in diameter at the back of rats and studied healing at 3, 7, 14 and 21 days. The wound contraction and epithelialization were assessed by peripheral digital planimetry and myofibroblasts by immunohistochemistry with a-SMA.There was no difference between groups regarding wound contraction. In wounds treated with metronidazole peripheral epithelialization was evident early on day 3 (p <0.001) and there were no differences in other periods. In the control group, the number of myofibroblasts was higher on day 7 (p = 0.003) and day 14 (p = 0.001) and in the experimental group it was suggestively higher on day 3 (p = 0.06).Metronidazole 4% solution at a dose of 50 mg/kg applied topically to wounds healing by secondary intention facilitates early peripheral epithelialization, does not interfere with wound contraction and delays the appearance of myofibroblasts.