Ketamine is a new party drug, which is easy to obtain. For this reason, it is possible that physicians will be increasingly confronted with users that have medical problems. Relatively few cases of ketamine intoxication with a fatal outcome have been reported thus far. Ketamine is very hallucinogenic; people can experience unpleasant flashbacks even weeks after the drug has been eliminated from the body. Ketamine has a short half-life; the elimination half-life is about 2.5 h. A serious intoxication can lead to aspiration, acidosis, rhabdomyolysis, epileptic seizures, respiratory depression, and cardiac arrest. Ketamine is frequently used as a party drug in combination with other substances. As a result, the chance of untoward effects is increased. Anaesthetists use ketamine for short surgical procedures, sedation and analgesia. It is also used more and more often as an analgesic in patients who do not respond well to opioids.