Silymarin, an extract from Silybum marianum, has been shown to have antioxidant properties. However, there is no scientific report on wound healing activity of the silymarin. The purpose of this study was to evaluate the effect of topical administration of silymarin on excision wound healing in rats. Excision wounds were made on the back of rats. Rats were divided into three groups, as control, vehicle, and treatment. Vehicle and treatment groups received polyethylene glycol and silymarin dissolved in polyethylene glycol, respectively. The control group did not receive any treatment. The wound tissues were removed on 5th, 10th and 15th day for histopathological analysis and total collagen determination by hydroxyproline assay. Results showed that silymarin increased epithelialization and decreased inflammation but did not have any effect on percentage of wound contraction, collagenization and hydroxyproline levels. It was concluded that silymarin can significantly stimulate epithelialization and reduce inflammation in full-thickness wounds in rats.