Objectives: To determine the time from symptom onset to hospital admission of patients with suspected acute stroke, final diagnoses and patient eligibility for thrombolytic therapy. Design: Hospital-based, prospective, observational study. Setting: Royal Adelaide Hospital Stroke Unit, South Australia. Patients: All patients admitted to the unit with suspected acute stroke over 11 months (11 April to 10 October 2000 and 20 August 2001 to 19 January 2002). Main outcome measures: Time from symptom onset to admission; final diagnosis. Results: Of 284 patients admitted, 39 (14%) had diagnoses other than stroke (including eight with transient ischaemic attacks), 42 (15%) had haemorrhagic stroke and 203 (71%) had ischaemic stroke. Median time to admission after symptom onset was 6 hours (range, 30 min to 13 days), with 100 patients admitted within 3 hours of symptom onset (35%), and 80 within 2 hours (28%). Thirty-seven patients (13%) could have been considered for thrombolysis (diagnosis of,non-severe but disabling ischaemic stroke and admission time < 3 hours). Location at stroke onset was the only independent predictor of time to admission. Conclusions: Most patients with stroke do not present urgently to the emergency department, rendering them less likely to be considered for thrombolytic therapy.