Background: Aluminum phosphide (ALP) poisoning causes severe fatal complications as it affects vital organ functions, which could be assessed by arterial blood gases analysis. Aim of work: is to investigate the role of arterial blood gases level in prediction of the severity of acute aluminum phosphide poisoning. Subjects and Methods: The study data were collected from hospital admission records of 30 adult acutely ALP intoxicated cases at PCC-ASU, grouped into minor, moderate, severe and fatal groups according to PSS. Results: A Highly significant difference was found between the groups regarding blood pH, serum bicarbonate and lactate levels, mean arterial blood pressure, body temperature. A significant difference was revealed regarding cold extremities, pallor, peripheral cyanosis, irritability, Post hoc test showed significant difference between minor and severe, minor and fatal, moderate and fatal groups regarding blood pH, HCO₃ level and serum lactate, severe and fatal groups regarding serum lactate. Conclusion: Arterial blood gases parameters including serum bicarbonate, lactate and lood pH has predictive value for severity in acute ALP cases. Recommendations: Further studies are needed on larger samples studying other predictive factors.