Purpose: The optimal dose of oximes for use in the treatment of organophosphorus pesticide poisoning has not been conclusively established. In this retrospective study, we assessed the effectiveness of the use of high-dose pralidoxime infusion in treating organophosphorus pesticide poisoning. Methods: From January 1998 to December 2009, 71 patients visited the hospital Emergency Department (ED) as a result of organophosphate pesticide intoxication. All of these patients received an initial bolus of 2 g of pralidoxime as the first step of treatment. Patients who then received continuous infusion of pralidoxime at a dose of 500 mg/hr were entered into study group 1 (low dose), and those treated by continuous infusion of pralidoxime at a dose of 1000 mg/hr were entered into study group 2 (high-dose). Plasma cholinesterase activities for each patient were evaluated at ED arrival and re-evaluated 24 hours after pralidoxime infusion. The effectiveness of the two treatment modalities was gauged by comparing the required duration of mechanical ventilation, time spent in the intensive care unit (ICU) and total time spent in the hospital. Results: The mean duration of mechanical ventilation was $9.98{pm}6.47$ days for group 1 and $4.39{pm}6.44$ days for group 2. The respective mean duration of time spent in ICU and the total number of days in the hospital were $16.38{pm}18.84$ days and $21.87{pm}20.16$ days for group 1, and $7.83{pm}9.99$ days and $11.71{pm}13.53$ days for group 2. Highdose pralidoxime treatment was associated with shorter required durations for mechanical ventilation, ICU and hospital stay. In addition, plasma cholinesterase reactivation rates were higher for those patients receiving high-dose pralidoxime treatment. Conclusion: The results suggest that high-dose pralidoxime treatment has greater efficacy for patients suffering from organophosphorus pesticide poisoning.