AN experiment conducted at the department of veterinary public health, college of veterinary medicine, Mosul-Iraq, during September to October 2009 to study the effect of Mycofix ® plus (MY) on broiler health performance during aflatoxicosis Eighty, one- day- old commercial male broiler chicks (Ross 308), were distributed to 4 dietary treatment groups with 2 replicates of 10 chicks each. Birds were reared for 35 days. All birds were fed on diet with or without aflatoxin (AF), and with or without (MY) in feed. The treatment groups were as follow: G1 (0 part per million (ppm) AF without MY); g2 (2.5 ppm AF without MY ); g3 (0 ppm AF & 0.25% MY ); G4 (2.5 ppm AF & 0.25 % MY ). Body weights and feed intake were recorded weekly. At 35 of bird’s age, five birds were randomly selected from each group for estimation of WBCs, RBCs, HB and ESR; glucose, total protein, cholesterol, and triglycerides; serum levels of AST,ALT and ALP enzymes; antibody titers and CV% against Newcastle disease (ND) vaccine; relative weights of bursa of Fabricious , thymus, spleen, proventriculus, gizzard, kidney, liver, heart and pancreas, in addition to recording liver lesions. Results show that MY was effective in ameliorating the negative effect of AF on growth performance (body weight gain ,feed consumption and feed conversion ratio); on relative weights of affected internal body organs and the score lesion of liver; on blood picture (WCS, HB and glucose); serum enzymes (AST, ALT and ALP); antibody titer and CV% against ND vaccine in comparison to AF contaminated feed and control groups.