The Skaraborg Hypertension Project is a 5-year trial testing the impact of structured hypertension care implemented in half of the country, the other half serving as control. Population investigations revealed improved blood pressure control in all treated hypertensives in the study area, blood pressure reduction averaging 2-5 mmHg. The primary trial hypothesis of a possible impact on stroke incidence in the community was tested in this study. Cases of fatal and non-fatal stroke were identified from local and national mortality and morbidity registers, and diagnoses were validated against medical records. Of an initial 1169 reported cases, 1097 proved to be true stroke after validation. A statistically significant difference in stroke incidence trends (fatal and non-fatal) between the study and control populations was identified (P = 0.0251). Improved hypertension control in the study area seems the most plausible explanation for the relative decline in stroke incidence in the study area.