The aim of this study to assess Rabbit Syndrome (RS) in case of Olanzapine treatment patients with Bipolar affective disorder. Rabbit syndrome (RS) is an antipsychotic-induced rhythmic motion of the mouth/lips resembling the chewing movements of a rabbit. The movement consists of a vertical-only motion, with no involvement of the tongue. Long-term exposure to typical antipsychotics has clearly been associated with RS, but little is known of the risk of RS due to exposure to newer atypical antipsychotics. There have been isolated reports of RS in patients treated with the atypical agents Olanzapine, Risperidone, Aripiprazole and Clozapine. We have observed two cases of Rabbits syndrome in a 45 year old female diagnosed with bipolar affective disorder and 35 year old male patient diagnosed with generalized anxiety and depression treated with Olanzapine.