Abstract: Objective To understand the causes of acute occupational poisoning, in order to prevent such cases. Methods The data of 70 cases of patients with acute occupational poisoning treated in Dapeng New District of Shenzhen City during March 2011 to September 2014 were analyzed retrospectively. Results Chemicals causing intoxication varied dramatically, in which arsenic hydrogen, toluene and chlorine gas accounted for 24.33%, 25.71% and 28.57%, respectively. There were 5 death cases reported, caused by hydrogen sulfide (2 cases), carbon monoxide (2 cases) and ammonia gas (1 case). The causes of acute occupational poisoning included violation of safety operation specification, lack of safety knowledge, non-use of personal protective equipments, no ventilation equipment and accidents, among which the violation of safety operation specification accounted for 71.43%. Conclusion The causes of acute occupational poisoning varied often. The pertinence measures should be taken to control the risk of acute occupational poisoning.