Ketamine has been the commonest abusive substance used by Hong Kong teenager since 2005. It is also the fourth commonest poison encountered in Hong Kong Poison Information Centre (HKPIC) poisoning data in 2010. From June 2008 to July 2011, HKPIC managed 188 and 96 cases of acute and chronic ketamine poisoning, respectively, which reflect its acute and chronic toxicity pattern. Demographically, there is a male predominance, and the majority is between the ages of 10-39. For the acute cases, 48 % presented with neurological features such as confusion, drowsiness, or transient loss of consciousness which usually subside with supportive care in a few hours. For the chronic cases, 92 % of them presented with features of ketamine cystitis while about 66 % presented with chronic abdominal pain. The current understanding of ketamine cystitis and chronic abdominal pain will be reviewed. Management is primarily symptomatic measures and most importantly abstinence from ketamine use.