The effects of Aflatoxin (AF) (0.0 and 0.5m g kg-1) and High Grade Sodium Bentonite (HGSB) (5, 7.5 and 10 g kg-1) were tested in an in vivo study including 8 dietary treatments with three replicates of 14 birds per diet per replicate, using a total of 336 broiler chicks up to five weeks. Results showed that chicks receiving AF contaminated feed had significantly (P 0.05) suppressed body weight gain, which improved significantly (P 0.05) with addition of HGSB to AF contaminated diet. Supplementation of HGSB at 7.5 and 10 g kg-1 to the diets containing AF significantly (P 0.05) improved feed consumption by 9.97 and 9.15 g kg-1, respectively, compared to the control group. Efficiency of feed utilization decreased significantly (P 0.05) with addition of 0.5 mg kg-1 AF and improved significantly (P 0.05) in HGSB treated group. The relative weights of liver and kidney, which increased significantly (P 0.05) with addition of 0.5 mg kg-1 AF (19.56 and 18.38 g kg-1) compared to control group, were improved with dietary inclusion of 7.5 and 10 g kg-1 HGSB. Relative weights of gizzard and pancreas were not affected in AF fed and the control groups. The relative thymus and bursal weights were significantly (P 0.05) lower at inclusion of 0.5 mg kg-1 of AF (38.99 and 31.36%) compared to the control group, but were not altered by supplementation of HGSB. The serum antibody titers against Newcastle disease (ND) and Infectious Bursal Disease (IBD) vaccination, which were significantly (P 0.05) depressed by AF, were restored with the inclusion of 7.5 and 10 g kg-1 HGSB. The serum concentration of uric acid and albumin in comparison with control group were not affected by treatment groups. The activity of serum gamma glutamyl transferase (GGT) significantly (P 0.05) increased in AF fed group and the addition of HGSB did not show significant reduction in the activity of serum GGT (P 0.05). Activity of serum alanine amino transferase (ALT) was not affected by the treatment gro
