Acetaminophen is one of the non-steroidal, anti-inflammatory drugs that have an analgesic and antipyretic properties in humans and other species. In chickchicks, neurotoxicity associated with acetaminophen is not fully known. The aims of this study was to identify the neurobehavioral, biochemical, and histopathological of acetaminophen in broiler chicks. The acute LD50 of acetaminophen was estimated by the up- and- down method, and then the influence of acetaminophen on the open field activity and tonic immobility tests was recorded. The behavioral signs and toxicity scores were recorded. The liver enzymes, aspartate transaminase (AST), and alanine transaminase (ALT) activities were estimated. Histopathology of brain and liver were performed. The acetaminophen LD50 value for 7 daysseven day old chicks was 1077mg/kg, intramuscularly. Acetaminophen reduced general locomotive activity of the chicks in the open- field arena as a result of a significant rise in latency to move from the central square and reduction in the numbers of lines crossed, as well as reduction of the vocalization score compared to control values. Intramuscular injection of acetaminophen at doses of 500 and 1000 mg/kg induced signs of toxicosis such as head dropping, closed eyelids, immobility, loss of vocalization, and recumbency, followed by death. Histopathological examination of the brain revealed the presence of congestion of blood vessels, vasogenic edema, and necrosis of Purkinje cells. Degenarative chengesDegenerative changes and liver enzyme functions showed liver dysfunction. Our resultresults show the behavioral, biochemical, and histopathological data that acetaminophen at higher doses produced acute neurotoxicity in chicks.