Objectives : To estimate the annual socioeconomic costs of stroke in Korea in 2005 from a societal perspective. Methods : We identified those 20 years or older who had at least one national health insurance (NHI) claims record with a primary or a secondary diagnosis of stroke (ICD-10 codes: I60-I69, G45) in 2005. Direct medical costs of the stroke were measured from the NHI claims records. Direct non-medical costs were estimated as transportation costs incurred when visiting the hospitals. Indirect costs were defined as patients and caregivers productivity loss associated with office visits or hospitalization. Also, the costs of productivity loss due to premature death from stroke were calculated. Results : A total of 882,143 stroke patients were identified with prevalence for treatment of stroke at 2.44%. The total cost for the treatment of stroke in the nation was estimated to be 3,737 billion Korean won (KRW) which included direct costs at 1,130 billion KRW and indirect costs at 2,606 billion KRW. The per-capita cost of stroke was 3 million KRW for men and 2 million KRW for women. The total national spending for hemorrhagic and ischemic stroke was 1,323 billion KRW and 1,553 billion KRW, respectively, which together consisted of 77.0% of the total cost for stroke. Costs per patient for hemorrhagic and ischemic stroke were estimated at 6 million KRW and 2 million KRW, respectively. Conclusions : Stroke is a leading public health problem in Korea in terms of the economic burden. The indirect costs were identified as the largest component of the overall cost.