Background & objective: organophosphate (OP) insecticide poisoning is considered a major clinical problem, especially in developing countries with a 15–30% case fatality rate. These compounds act by inhibition of acetylcholinesterase enzymes, with clinical features of muscarinic overstimulation. Treatment mainly depends on muscarinic receptor antagonist, atropine, to relieve the symptoms of intoxication. This study aims to assess the benefits of adding nebulized atropine to infusion during the treatment of severe OP poisoning cases. Patients & methods: This cross-sectional observational study was conducted on 40 patients aged 18 to 58 years who were admitted with acute severe OP poisoning at the Poison Control Center of our university from September 2019 to August 2020. After first aid measures, the patients were divided randomly into two groups; the first group received atropine by infusion, while the second group was treated by nebulized and infused atropine. The following data were evaluated and compared between both groups; total atropine dose, oxime dose, heart rate, peak inspiratory pressure, plateau pressure, the number of endotracheal tubes used, development of pneumonia, total time of ventilation, and the number of survivors. Results: The results revealed that the cases who received atropine by the nebulizer and parenteral routes required a lesser dose of atropine for abolishing muscarinic symptoms, showed a significant decrease in plateau and peak inspiratory pressures, lower incidence of development of pneumonia, decreased need for chest tube insertion and better survival rate. Conclusions: nebulized atropine, besides infused one, would have many benefits with future considerations.