We wanted to assess habitual snoring as a credible risk factor for acute vascular disease, mainly stroke and myocardial infarction. The patients selected for the study had been admitted to the hospital through the emergency department, and were evaluated by means of multidimensional interviews and clinical records: 164 had acute cerebrovascular disease, and 136 cardiovascular disease; 330 patients with nonvascular disease were the controls. The evaluation showed 48% of vascular disease patients to be habitual snorers, but only 30% of the controls; the difference was statistically significant. Compared with the controls, in the cerebrovascular patients the risk (odds ratio) associated with habitual snoring was significantly increased, and of the same order as the risk associated with age over 65 yrs, male gender, diabetes mellitus, and dyslipidaemia; whilst the risk associated with hypertension was higher. In the cardiovascular patients, the risk associated with habitual snoring was again significantly increased and of the same order as the risk associated with male gender, body mass index > 29 (kg.m-2), dyslipidaemia, heavy smoking, excessive alcohol intake and hypertension. A logistic regression analysis, entering the variables in the following order: age, gender, body mass index, diabetes, dyslipidaemia, smoking, alcohol, hypertension, and habitual snoring, showed that habitual snoring carries a significant risk factor for stroke and myocardial infarction, even after adjusting for other factors. Since habitual snoring carries a definite risk for acute vascular disease, we conclude that inquiring about it should become routine practice.