Stroke is the third leading cause of death and the most important cause of long-term disability in Italy and other developed countries, heavily influencing quality of life and costs of health care. In spite of the widespread occurrence of the disease and its relevant impact in Italy, there is neither a national nor a regional surveillance system of cerebrovascular diseases. A regional surveillance system for stroke has two important aims: to help to interpret the geographical and temporal trends of the disease for health care planning and resource allocation and to allow close monitoring of the quality of stroke services. Age-standardized mortality rates for cerebrovascular diseases in the Lazio region (5,242,709 inhabitants) in the period 1998-99 were 69.4 for males and 59.4 for females per 100,000 inhabitants. In the year 2000, about 3% of all hospital discharges were for cerebrovascular diseases with a hospitalisation rate of 4.36 per 1000 inhabitants. The mean length of stay is 12 days (median of 9 days) and in-hospital death is 15.4%. The admission rate for cerebrovascular diseases to emergency departments is 3.40 per 1000 inhabitants. The goal of the Lazio Regional Health Authority is to implement a surveillance system for stroke based both on current data (mortality and discharge data) and on information collected in a registry for quality assessment of stroke care. The first step of the study is to develop a regional register of acute stroke using an 'ad hoc' data sheet integrated in the computer-based patient record system of clinical and administrative data (GIPSE) operating in all emergency departments in the region.