OBJECTIVE: Stroke is a major cause of morbidity, health service use, and death in the UK. Previous studies report substantial associated costs, particularly related to hospitalisation. However, no previous UK analysis has used data from a population-based incidence study with full case ascertainment, without which major inclusion bias is likely. Using data from such a study, we estimate the acute costs per patient over the first year from initial stroke, by severity of stroke and prior atrial fibrillation. METHODS: Event and hospitalisation (inpatient or outpatient) data were obtained from the Oxford Vascular Study, a prospective cohort study of all individuals in 9 general practices in Oxfordshire, UK, which identified 346 patients experiencing a stroke from April 1, 2002 - March 31, 2004. Transient ischaemic attacks were excluded. Mean costs per patient were calculated, adjusting for censoring. RESULTS: In all, 212 (62%) patients were admitted, the remainder being managed in the outpatient clinic. The mean censoring-adjusted cost per patient was GBP6,508, 69% of which was incurred within 60 days after the index event. Patients with stroke recurrence in the study period incurred costs of £7881 compared to GBP6089 in those without. Costs in patients with prior atrial fibrillation were £9757, compared with £5687 in those without (p=0.028). Patient costs by stroke severity (28-day Rankin score 0/1 = mild, 2/3 = moderate, 4/5 = severe, 6 = dead) were £1138, £7471, £18181, and £1602. CONCLUSIONS: We derived reliable and up-to-date estimates of acute care costs associated with stroke over the first 12 months, using data from an “ideal” population-based incidence study. The impact of severity of initial stroke and of prior atrial fibrillation on subsequent costs. Our estimates, which will be extended as follow-up continues, should be of value to analysts interested in assessing the burden of stroke and the cost-effectiveness of interventions.