Purpose: Dichlorvos has been in widespread use as an organophosphate (OP) insecticide compound. The purpose of this study was to access the epidemiology and clinical features of dichlorvos in Korea. Methods: This was a 38 multi-center prospective study of dichlorvos poisoning using surveys, a structural reporting system and review of hospital records from August 2005 to July 2006. A total of 54 patients with acute dichlorvos poisoning on a national basis were enrolled. We analyzed the epidemiologic characteristics and clinical manifestations of dichlorvos poisoning. In addition, the clinical features of dichlorvos poisoning were compared with others OP compounds. Results: During the study period, compounds involving pure OP poisoning were dichlorvos (22.7%), methidathion (8.4%), and phosphamidon (6.7%). In acute dichlorvos poisoning, all ingestion routes were oral. Intentional poisoning involved 74.1% of cases. The common initial complaints involved gastrointestinal (64.8%), systemic (61.1%), central or peripheral nervous system (53.7%), and respiratory symptoms (50.0%). The median arrival time to hospital after dichlorvos poisoning was 2.6 hours and mean hospitalization duration was 7.1 days. 2-PAM was administered in 35 patients in mean doses of 6.3 g/day intravenously. Atropine was administered in 30 patients with a mean dose of 62.8 mg/day (maximal 240 mg/day). Overall mortality rate for dichlorvos poisonings were 14.8% (8/54). Immediate causes for death included sudden cardiac arrest or ventricular dysrhythmias (50%), multi-organ failure (25%), acute renal failure (12.5%), and unknown causes (12.5%). Conclusion: When compared to previous reports, dichlorvos poisoning displayed relatively moderate severity. The presence of a lower GCS score, altered mental status, serious dysrhythmias, systemic shock, acute renal failure, and respiratory complications upon presentation were associated with a more serious and fatal poisoning.