Objective: The purpose of the present study was to clarify the present status of stroke medicine in Japan using a hospital-based, prospective registration study of 156 hospitals from all over Japan. Methods: Consecutive patients with acute ischemic stroke and transient ischemic attack (TIA) who presented to hospital within 7 days of onset from May 1999 to April 2000 were enrolled in this study. A common protocol was applied in every participating hospital. Results: A total of 16,922 patients (TIA, 6.4%) with a mean age of 70.6 ± 11.5 years (median 71 years, range 18–107 years) were enrolled in the study. Lacunar stroke was the most frequent stroke subtype (38.8%), followed by atherothrombotic (33.3%), cardioembolic (21.8%) and other stroke (6.1%). NIHstroke scale score on admission was 8.0 ± 7.9 (median 5; 25th to 75th percentile, 2–11). 36.8% arrived at hospital within 3 h of symptom onset, and 49.5% within 6 h. The ambulance was used for 70.2% of patients arriving within 3 h after onset, but in only 29.9% of patients visiting the hospital later than 3 h after onset (p < 0.0001). 60.8% displayed good outcome (modified Rankin Scale score of 0–2 at discharge), while 32.3% displayed poor outcome (score 3–5), and mortality rate was 6.9%. Conclusions: More than half of the acute stroke patients arrived at hospital later than 6 h after onset. Establishment of ideal emergency systems is needed for better management of stroke and for improvement of patient outcome, in particular, in the future after approval of intravenous recombinant tissue plasminogen activator for acute ischemic stroke by the Japanese government.