This study investigated whether dietary supplementation with N-acetylcysteine (NAC) could prevent negative effects from aflatoxin B1 (AFB1) intoxication in broiler chickens. Chickens were fed either a control diet, AFB1 alone at 3 mg/kg, NAC alone at 800 mg/kg body weight, or a combination of AFB1 and NAC. Results showed that NAC decreased the severity of AFB1 toxicity effects by improving body weight gain, feed conversion, liver and kidney health, and decreasing plasma ALT activity. NAC was able to prevent many of the harmful impacts of AFB1 intoxication in broiler chickens without affecting normal production parameters.