Aflatoxin B₁ (AFB₁) is an immunosuppressive plant-origin toxin that reduces disease resistance of fish. A total number of 360 fries of the common carp, Cyprinus carpio(0.50 g/fish b.w.) were subdivided into 6 groups (G₁-G₆). Fish were fed on an AFB₁-contaminated diet at a dose of 0.5 and 1.0 mg/kg fish feed in G₂ and G₃, respectively. AFB₁-contaminated diet plus nucleotides (NT) supplementation (at 0.2% instead of normal corn) were G₅ and G₆, respectively. Fish in G₁ were fed on a diet free from AFB₁ and NT while in G₄, fish were fed on a diet free from AFB₁ and supplemented with NT. Growth performance and liver enzymes (ALT, AST, and ALP) were adversely impacted by feeding on a contaminated diet and NT supplementation could ameliorate such withdraws. Anti-inflammatory IL-10 was increased in groups fed on contaminated diet indicating that inflammation had taken place. Feeding on AFB₁-contaminated diets resulted in degenerative changes (hepatic and spleen tissues), NT-supplementation could relieve such changes (low dose of AFB₁) however impacts of the high dose of AFB₁ were severe to a degree that NT-supplementation could not effectively diminish it. Regardless of feeding on the contaminated diet, C. carpio supplemented with NT could resist Aeromonas hydrophila infection even those fed on contaminated diets, while un-supplemented groups showed higher mortality rates. A. hydrophila could isolate even after 35 days of experimental infection in C. carpio fed on AFB₁-contaminated diet (G₂ and G₃).  It concluded that NT supplementation could ameliorate the adverse health impacts associated with feeding diet contaminated with AFB₁ in C. carpio.