Background: Organophosphates (OP) with high morbidity and mortality are one of the most common causes of poisoning especially in developing countries. Early diagnosis and appropriate treatment is often life saving as mortality rate of OP poisoning is still high. The objective of this study is to compare the accuracy of scoring systems (the sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score and glasgow coma scale (GCS)) in the prediction of mortality of acute organophosphate poisoning. 
Methodology: A retrospective and prospective study was done on 200 patients with acute OP poisoning admitted to the Poison Control Center (PCC), hospitals of Ain Shams University in the period between 1/1/2016 and 31/12/2016. Information was collected from the sheets and computerized data base of the patients. SOFA score, APACHE II score and GCS were calculated to each patient admitted. The results were revised, coded and organized for statistical analysis. 
Results: The study results revealed 180 (90%) patients recovered and 20 (10%) patients died. The area under the curve of receiver operator characteristic (ROC) of SOFA score was 0.995, for APACHE II score was 0.986 and compared to GCS was 0.977 with significantly higher SOFA and APACHE II scores in the died patients than in the recovered patients (P <0.001). As regards GCS there was statistically significant difference between recovered and died patients (P <0.001). 
Conclusion: It could be concluded that SOFA score, APACHE II score and GCS systems can be used to predict mortality of acute organophosphate poisoning with preference to SOFA score which had the highest accuracy and predictive ability. From the previous results, our study recommends that application of SOFA score, APACHEII score and GCS are good predictors of high mortality in OP intoxicated patients which helps in proper allocation of resources particularly for intensive care unit patients.