Antiphospholipid syndrome (APS) is one of the uncommon causes of ischemic stroke, and is associated with young and female patients. However, the significance of antiphospholipid antibody (aPL) in older ischemic stroke patients is uncertain. We aimed to examine the significance of aPLs in ischemic stroke in these older patients.A total of 739 patients with acute ischemic stroke within 7 days of initial symptoms were collected consecutively. Clinical and laboratory data were obtained from medical records. aPLs (lupus anticoagulant, anti-cardiolipin antibody, anti-β2glycoprotein-I antibody) were measured the day after admission and the presence of at least one antibody was regarded as positive aPL. Patients with positive aPL were rechecked after at least 12 weeks for confirmation of APS.Of the 739 patients, 103 (13.9%) had at least one aPL initially. These patients were older, had more atrial fibrillation and higher levels of inflammatory markers. Among the 103 aPL positive patients, 41 remained positive at 3 months, 23 showed negative conversion, and 39 were not available for follow-up. Patients diagnosed with APS had higher numbers of aPL and had specifically anti-β2glycoprotein-I IgG antibody. The patients with aPLs did not differ significantly from the others in terms of stroke subtype.aPL was rather common in ischemic stroke patients regardless of age. Although the influence of transient positive aPL on ischemic stroke remains uncertain, two or more aPLs and the presence of anti-β2glycoprotein-I IgG may predict a diagnosis of APS.