Background: COMMITTING SUICIDE is a worldwide problem. Previous reports have revealed the high prevalence of COMMITTING SUICIDE in Iran.Nowadays, drugs, chemical agents, and poisons are widely available. Drugs are more commonly used for COMMITTING SUICIDE. The present study was carried out to determine the frequency of poisoning with chemical agents or drugs in hospitalized patients referring to Loghman Hakim hospital in winter 1999.Methods: In winter 1999, we have randomly selected 500 patients, including 313 females and 187 males, hospitalized in Loghman Hakim hospital due to poisoning. A questionnaire was filled.Results: Patients have used the following materials for COMMITTING SUICIDE: drugs (83.3%) poison for rodents (4%), chemical agents (3.8%), opium (7.6%), and alcohol (7.7%). Of drugs, benzodiazepines (17%) and TCAs (6%) were more frequently used. Meanwhile, ratsbane was used by 17%. Conclusion: Of hospitalized patients, 10.3% had required intensive cares. Almost all the patients aged 15-77 years. 75.8% had informed their family in advance, thus, threatening to COMMITTING SUICIDE should be taken serious.