Abstract Organophosphorus compound poisoning is one of the most common poisonings often requiring ICU care and ventilatory support. Hence, this study has been undertaken to identify the factors, which predict the need for ventilation in these patients. All the patients who were diagnosed to have consumed organophosphorus compound poison who presented within 24 hours of consumption were included in the study. Patients with concomitant respiratory illness double poisonings were excluded from the study. Of the 12 patients who has oxygen saturation levels < 89%, 8(33.33%) required ventilation. Ventilation was required by 46% of patients who had a GCS score of <10. 38% of patients with a fasciculation score of > 4 required ventilations. Of the patients admitted to the hospital > 4 hours after consumption of poison, 70% required ventilation. 5% of patients with mild and 20% with moderate poisoning required ventilation. In contrast 75% of patients with severe poisoning required ventilation. Patients who were ventilated required a higher dose of atropine within 48 hours of admission as compared to those who were not ventilated. Patients who presented with higher respiratory rate, accessory muscles of respiration in action, higher fasciculation score, GCS-score of <10, greater time lag between consumption of poison and admission to hospital (>4 hours), Pinpoint (<2) pupil, severe grade of poisoning, low values of Pseudocholinesterase and O2 saturation <89% were more likely to require ventilation.