This study evaluated a novel use of the traditional Asian herb Anoectochilus formosanus. This plant is a traditional food item, generally used for the treatment of liver disorder, hepatitis, hypertension, diabetes, cardiovascular disorder, etc. In this study, the root, stem, and leaf of A. formosanus were used as substrates for lactic fermentation. The fermentation products were analyzed for their total antioxidant activity, reducing power, and scavenging effect on superoxide anion radicals and hydrogen peroxide. The pH of the fermentation medium reached its lowest value, 3.5, at the 35th hour of fermentation. Antioxidant activity of A. formosanus was found to be 61-78%. Lactobacillus longum-led fermentation exhibited the greatest reducing power with an average of 0.3. The products of fermentations utilizing the three plant parts as substrates exhibited a similar scavenging activity (27-30%) on free radicals. This study may suggest a novel use of lactic-fermenting A. formosanus in the production of functional food. (C) 2010, The Society for Biotechnology, Japan. All rights reserved.