Purpose: Glyphosate is widely used and its toxic exposures are not rare. Occasionally, glyphosate intoxication can lead to death. The aim of this study is to analyze clinical findings and fatality in glyphosate intoxication. Methods: Clinical data on acute glyphosate intoxication were prospectively collected at 28 hospitals nationwide between August 2005 and July 2006. The patients' clinical symptoms and characteristics of fatalities were investigated and statistical analysis was performed. Results: Among 105 patients who were finally included, gastrointestinal symptoms(59%) were the most common. A significant difference in the amount ingested was observed between patients with higher systolic blood pressure and those with systolic blood pressure less than or equal to 80 mmHg (p<0.001). The more the patients ingested, the more aggravated their mental status became (p=0.004). Seven patients(6.7%) died, and all of them had ingested greater than or equal to 200 ml. Patients who died had ingested greater amounts than the survivors (p<0.001), and their mental status was worse (p<0.001), and systolic blood pressure was lower (p<0.001). According to the result of logistic regression analysis, relative risk was 24.1-fold higher in the 'poor' mental status group compared with 'good'. Conclusion: Patients who ingested large amounts of glyphosate showed poor mental status and lower blood pressure. Statistical difference in amount ingested, mental status, and systolic blood pressure was observed between survivors and patients who died. Ingested amounts and mental status were the most important factor of the prognosis of glyphosate intoxication.