Aflatoxins (especially Aflatoxin B₁) contaminate human and animal foods and cause reduced productivity, suppressed immune function, reduced reproductive ability and liver damage. The objective of this randomized, controlled study was to investigate the influence of the Chinese herbal medicine Long Dan Xie Gan (LDXG) on hepatic antioxidant capacity in ducklings administrated AFB₁. Ninety 7-day-old ducklings were randomly divided into three groups (Groups I–III) containing 30 birds each. Group I was a control group. Group II was administered AFB₁ (0.1 mg/kg body weight) orally for 21 days. Group III was administered AFB₁ (0.1 mg/kg body weight) orally plus LDXG (as 2% of the feed) for 21 days. On the 7th, 14th and 21st days of treatment, 10 ducklings (5 males and 5 females) were randomly selected from each group, euthanized and 1 gram of liver was removed. The activity of hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in Group II (AFB1 only) ducklings was significantly decreased (p<0.01) and the levels of hepatic malondialdehyde (MDA) significantly increased (p<0.01), when compared to Group I (no AFB₁ or LDXG) showing the adverse effects of the AFB₁. The activity of hepatic SOD, CAT, GSH-Px and GR was significantly higher (p<0.05) and MDA significantly lower (p<0.05) in Group III (AFB₁ + LDXG) compared to Group II (AFB₁ alone) indicating antioxidant effects of LDXG. The AFB₁ impairs hepatic antioxidant capacity, but LDXG significantly ameliorated the negative effects of AFB₁ and may be a useful antioxidant supplement to duckling feed sources.