Olanzapine is an atypical antipsychotic drug that is being increasingly used as an intentional overdose. It usually presents with reduced and fluctuating level of consciousness and coma. It may rarely present with muscle toxicity by binding to HT2A receptor in skeletal muscle and increasing its permeability. We report a case of such poisoning which had no obvious symptoms but was brought to emergency due to overdose and was found to have acute muscle toxicity as evidenced by raised creatine phosphokinase (CPK) levels. From this, we also want to emphasize that CPK levels should be checked in all the patient's prescribed olanzapine to look for muscle toxicity.