Abstract: In vitro and in vivo studies were conducted to evaluate the efficacy of modified palygorskite (MP) to alleviate the toxic effects of aflatoxin (AF) B₁ in ducks.In vitro results indicated that MP was much more efficient to adsorb AFB₁ than palygorskite. In the in vivo study, four hundred and eighty Cherry Valley commercial ducks, 1 day old, were randomly allocated to four treatments for 42 days, which included: 1) Basal diet (control); 2) Basal diet supplemented with 0.25% MP; 3) Fifty percent of the corn in the basal diet was replaced by moldy corn and the concentrations of AFB₁ in prophase and anaphase are 50 and 55 μg/kg of diet, respectively; 4) The third diet plus 0.25% MP. The addition of MP to chick diets at a level of 0.25% had no significant effects on duck performance, AFB₁ contents in tissue and serum, organ weights, or serum biochemical index. In ducks fed the diet containing moldy corn alone, the performance was significantly decreased, the AFB₁ contents in breast muscle, liver, kidney or serum, the relative weights of the heart, liver, kidney, pancreas and the levels of serum glutamic-oxaloacetic transminase, glutamic-pyruvic transminase, amylase were significantly increased, and the concentrations of serum total protein, albumin, uric acid were significantly decreased. Ducks fed the combination moldy corn / MP diet had similar performance, AFB₁ contents in tissue and serum, organ weights, and serum biochemical index to those of control ducks. These results indicated that MP was effective in preventing the toxic effects of AF in ducks.