Sudden death is unexpected death within 24 hours from the onset of symptoms with or without known preexisting conditions. Respiratory pathologies are the second most common cause of such deaths. 39 years old male patient with a history of mental illness for the last 10 years and on regular treatment with antipsychotic medications, suffered sudden deterioration of higher functions and was admitted to the Medical College, and Hospital, Kolkata with a provisional diagnosis of drug toxicity. He succumbed to his condition within 24 hours of admission and the dead body was referred to Kolkata Police Morgue for a medicolegal autopsy.Shows multi-system involvement in the form of Pulmonary Oedema, consolidation, broncho-pneumonic changes and subpleural petechiae, Cardiomegaly due to biventricular hypertrophy, Cerebral Oedema, Enlarged kidneys with loss of cortico-medullary differentiation and streaky cortico-medullary haemorrhages. Stomach findings were unremarkable.1) Toxicological Examination of blood, bile, vitreous and routine viscera was negative for any poison or pharmacological agents.2)Histopathological examination with routine H&E staining showed Pulmonary oedema with lymphocytic infiltration and the presence of fat and hematopoietic precursor cells in pulmonary vessels, Interstitial Oedema and focal glomerulosclerosis and Periportal inflammation in the liver.