Objectives: To estimate the need for post-acute care (PAC) and to determine the factors related to that need for stroke patients in Taiwan. Methods: All new cases of stroke reported to the National Health Insurance Database (NHID) in 2005 were identified in this retrospective cohort study. Prolonged hospital stay (PHS, ≥29 days), readmission within 1 to 14 days, and combined PHS with readmission were the proxies for estimating the need for PAC. Multilevel analysis was used to examine the relationships among patients, hospital characteristics, and the need for PAC. Results: Risk markers for the need for PAC in stroke patients included male gender, age over 80, subarachnoid hemorrhage, comorbidity, index hospitalization in a division of rehabilitation medicine, and strokes related to surgery. Stroke patients hospitalized in medical centers were more likely to receive PHS while those hospitalized in district hospitals were more likely to be readmitted. Stoke patients with a prolonged hospital stay or readmission within 14 days were used as indicators to estimate the need for PAC; these accounted for 10.11-23.13% of stroke patients. PAC days accounted for 16.94-44.68% of the total length of stay. The hospital days per stroke patient may be reduced by 2.06-8.17 days, and hospital bed occupancy may be reduced by 306-1,210 beds after implementation of PAC. Conclusions: As many as 10.11-23.13% of stroke patients may need PAC. PAC payment/reimbursement policy may be considered in order to reduce acute medical expenditures.