Delirium is a neurobehavioral syndrome caused by dysregulation of neuronal activity secondary to systemic disturbances. It occurs in 35 to 80 % of critically ill, hospitalized patients. Recent estimates of in-hospital mortality rates among delirious patients have ranged from 25 to 33%.Based on arousal disturbance and psychomotor behaviour, the following three clinical subtypes of delirium have been described like hyperactive (hyper aroused, hyper alert, or agitated), hypoactive (hypo aroused, hypo alert, or lethargic), and mixed (alternating features of hyperactive and hypoactive types). Antipsychotics have been the medication of choice in the treatment of delirium. We report a case of hyper acute delirium due to parietal lobe lesion without any focal neurological deficit. While other metabolic causes were ruled out. Patient after pharmacological like antipsychotics as well as non pharmacological intervention showed partial improvement in few days. Thus we conclude that delirium is a serious cause and complication of hospitalization in elderly patients and should be considered to be a medical emergency until proven otherwise. For these reasons, prevention, early recognition and effective treatment of delirium are essential. Pathogenesis of delirium is incompletely understood. Right parietal and thalamic lesions have been reported most commonly among neurological causes.