Cerebral infarcts complicating heroin abuse have been seldom reported and only clinically and radiologically documented. We report a pathological case of cerebral infarct in a heroin sniffer. A 31 year old, male, heroin sniffing addict for several years, with no known past neurological history, was found dead one morning. The evening before, he had presented the usual signs of recent heroin intake. Opiates were found in large amounts in blood and urine. Post mortem HIV serology was negative. Post mortem examination revealed the usual signs of heroin addiction, but no cutaneous signs of IV drug use. Myocardial ischemic lesions of various ages involved the anterolateral part of the left ventricle; coronary arteries were normal. Neuropathological study revealed, partly cystic infarcts involving both cerebral hemispheres. They were mostly cortical with an intralaminar pattern and a watershed distribution at the boundaries between the territories of the anterior and middle cerebral arteries and the middle posterior cerebral arteries. Intracerebral vessels, large intracranial and cervical arteries were normal.