To determine if a history of snoring is a risk factor for brain infarction, I conducted a case-control study of risk factors for ischemic stroke using 177 consecutive male patients aged 16-60 (mean 49) years with acute brain infarction. For each patient I chose an age-matched (+/- 6 years) male control. Arterial hypertension, coronary heart disease, snoring (habitually or often), and heavy drinking (greater than 300 g/wk) were risk factors in the stepwise multiple logistic regression analysis. The odds ratio of snoring for brain infarction was 2.13. By McNemar's test this association increased strongly if a history of sleep apnea, excessive daytime sleepiness, and obesity were all present with snoring (odds ratio 8.00). My study indicates that snoring may be a risk factor for ischemic stroke, possibly because of the higher prevalence of an obstructive sleep apnea syndrome among snorers than nonsnorers.