A population-based cluster survey on stroke disorders was conducted for the first time in the city of Calcutta, India. The population surveyed totaled 50,291. The crude prevalence rate of stroke was 147/100,000 (age-adjusted prevalence 334/100,000). The annual incidence rate of stroke for the year 1998–1999 was 36/100,000 (age-adjusted annual incidence rate 105/100,000). Women outnumbered men regarding stroke prevalence in all age groups except in the 50- to 69-year age group. There were relatively more cases of cerebral haemorrhage in our study, compared to those in the western countries. Case-control analysis found hypertension to be the most significant risk factor for stroke.