Purpose: Many patients who are acutely poisoned with organophosphorus pesticides have co-ingested alcohol. The purpose of this study was to identify the factors that influence mortality in organophosphate intoxication and the differences between alcohol coingested patients and non-coingested patients, looking at vital signs, length of admission, cholinesterase activity, complications, and mortality. Methods: All patients visiting one Emergency Department (ED) with organophosphate intoxication between January 2000 and December 2012 were reviewed retrospectively. The patients were divided into two groups, alcohol coingested group and non-coingested group. Results: During the study period, 136 patients (alcohol coingested group, 95 patients; non-coingested group, 41 patients) presented to the ED with organophosphate intoxication. Seventy-one alcohol coingested patients (74.1%) vs. 16 non-coingested patients (39.0%) received endotracheal intubation, with results of the analysis showing a clear distinction between the two groups (p=0.001). Twenty-three alcohol coingested patients (24.2%) vs. 1 non-coingested patient (2.4%) required inotropics, indicating a significant gap (p=0.002). Twenty-eight alcohol coingested patients (29.5%) vs. 2 non-coingested patients (4.9%) died, with results of the analysis showing a clear distinction between the two groups (p=0.002). Conclusion: In cases of organophosphate intoxication, alcohol coingested patients tended to receive endotracheal intubation, went into shock, developed central nervous system complications, and more died.