Objective:To investigate the effect of mechanical ventilation on the patients with respiratory failure caused by acute poisoning. Methods: 28 patients with respiratory failure as a result of acute poisoning treated by mechanical ventilation were analyzed retrospectively. Results: 25 cases were cured and 3 cases were died. The time of mechanical ventilation were from 10 hrs to 9 days, the average time was 49.6 hrs. The complication associated with mechanical ventilation was that 21 cases suffered from pneumonia and 3 cases had low blood pressure. Conclusion: Mechanical ventilation on the case with respiratory failure as a result of acute poisoning is effective.