Effects of antioxidants on the collagen synthesis of fibroblasts from human hypertrophic scar tissues are not well known, however may be important in understanding pathogenesis of keloid or hypertrophic scar. We studied the effects of antioxidants, including butylated hydroxyanisole (BHA), superoxide dismutase (SOD), to the collagen in fibroblasts from hypertrophic scar tissue and normal tissue in culture. Antioxidants suppress the collagen synthesis of the fibroblasts from hypertrophic scar, however didn't suppress those of helthy normal tissue. These results suggest that antioxidants may be a useful therapeutic agent to hypertrophic scar and keloid.