The majority of acute toxic poisoning occur via oral route. The most important emergency treatment of acute poisoning are gastric lavage. Gastric lavage should be considered a patient has ingested a potentially life-threatening amount of a poison and the procedure can be undertaken within 60 mins of ingestion. But, gastric lavage does not consist properly in the cases of emergency situation or an inexperienced doctors treat. The purpose of this study was to determine whether gastric lavage is performed properly. Eighty patients were enrolled in the study in 12-month period from January to December 2002. A retrospective chart review was performed on patients identified as drug overdose who admitted to ER. To assess whether there was a subgroup of patients who may have been candidates for the initiation of gastric lavage in the ER. the patients divided in two groups by time interval from toxin ingestion to ER arrival. The group 1 that admit within 60 minutes after drug ingestion was 38 cases (47.5%), and the group 2 patient who admitted after 60 minutes was 42 cases (52.5%). The average age was 44±19 years in group 1, and 48±24 years in group 2. There were no differences in sexual distribution of two groups. The mean time interval was 49±20 minutes in the group 1, 258±190 minutes in the group 2. Only thirty (37.5%) of the patients had an overdose for which the treatment of gastric lavage was potentially feasible according to guideline. The correctly performed gastric lavage was 18 (47.4%) in group 1, 12 (28.6%) in group 2. We must enforce education about the gastric lavage, and do so that may treat according to guideline.