Gastric lavage is one of gastrointestinal decontamination methods which have been controversial in the clinical toxicology field for a long time. Expert groups of American and European clinical toxicologists have published the position papers regarding gastric lavage three times since 1997. They recommended that gastric lavage should not be used as a routine procedure in the management of acute intoxication, because they thought that there is no certain evidence of improving clinical outcome by its use. However, the studies they reviewed were not well-controlled randomized trials, which cannot be conducted in the clinical toxicology field due to variability of patients and ethical problems. Therefore, the results from these studies should be interpreted with caution. They also insisted that gastric lavage can be undertaken within 60 minutes of ingestion. The limitation of one hour after ingestion is too arbitrary and may cause a lot of misunderstanding. Formation of pharmacobezoar or gastric hypomotility after ingestion may significantly delay the gastric emptying time so that gastric lavage can be useful even after several hours or more in case of highly toxic substances or severe intoxication. Furthermore, as there are a number of serious intoxication by toxic pesticides with large amount in suicidal attempts in Korea, it seems that gastric lavage may be used more frequently in Korea than in Western countries. When deciding whether or not to use gastric lavage, all the indications, contraindications, and possible adverse effects should be taken into account on the basis of risk-benefit analysis. If the procedure is decided to be done, it should only be performed by well-trained experts.