Stroke has a high prevalence in Italy, and is the third cause of death worldwide. Hypertension is the most important risk factor contributing to the risk of stroke. The aims of this study were to assess the risk of stroke in a large cohort of hypertensive patients, and to determine the percentage with controlled blood pressure, to establish the contribution of this factor to the risk of stroke. The study involved general practitioners to make it representative of clinical practice. They were asked to recruit 10 consecutive hypertensive patients, treated and untreated. Data collection included a full medical history and a physical examination. The 10-year absolute risk of stroke was calculated by an algorithm derived, with some modification, from the Framingham study. Most untreated hypertensive patients were grade 1 or 2. In treated hypertensive patients, controlled blood pressure values occurred in 18.4%, the percentage being less in patients with left ventricular hypertrophy and diabetes. In diabetic hypertensive patients the more stringent blood pressure control recommended by the guidelines was achieved in only 3.0% of cases. The average 10-year stroke risk was 17%, a greater risk being more common in elderly patients, diabetic individuals and in those with left ventricular hypertrophy. Current antihypertensive treatment achieved blood pressure control in a limited fraction of hypertensive patients seen by general practitioners. The risk of stroke in hypertensive patients is by no means negligible, which emphasizes the need for more attention to be paid to the prevention of this disease.