The study was performed to investigate how often reduction of high blood pressure (> or = 220 mmHg systolic and or > or = 120 mmHg diastolic) was attempted in patients with acute stroke or transient ischemic attacks (TIA). Of 1351 consecutive patients with acute stroke or TIA 119 had high blood pressure on admission. In 15 patients the stroke was so severe that treatment was not considered. In the remaining 104 patients reduction of the blood pressure was attempted in 28 (27%); in 23 patients immediately following admission. None of the patients had symptoms or signs of hypertensive encephalopathy. It is concluded that reduction of high blood pressure in patients with stroke or TIA is attempted too often. As autoregulation is commonly impaired in acute stroke, reduction of systemic blood pressure may enhance ischaemic tissue damage. Reduction of blood pressure in acute stroke should be considered only in case of hypertensive encephalopathy.