introduction: olanzapine (zyprexa) has become one of the most commonly prescribed atypical antipsychotic drug in iran, at least in part due to its low potential to cause extra-pyramidal side effects. case: a 54-year-old man, who was a known case of schizophrenia from 10 years ago and within the recent years, was under periodic medical treatment by antipsychotic drugs. conclusion: neurologists a...