Background Research indicates that abnormal embolism caused by patent foramen ovale (PFO) may play an important role in cryptogenic stroke (CS). However, most researches has focused on young patients, and whether abnormal embolism caused by PFO also plays an important role in elderly CS is uncertain. The purpose of this study is to analyze the clinical characteristics of elderly patients with PFO, and to explore the correlation between elderly PFO and ischemic stroke.Methods 62 elderly patients diagnosed with ischemic stroke admitted to Qilu Hospital of Shandong University from April 2014 to April 2019 were selected as the Test Group. 62 non-stroke patients in our hospital's physical examination center and outpatient clinic were selected as the Control Group. Collect clinical data of patients for retrospective analysis.Results The incidence of PFO in the Test Group was significantly higher than that in the Control Group, the difference was statistically significant (p < 0.05). The proportion of large and medium shunt patients in the Test Group was significantly higher than that in the Control Group (p < 0.05). The proportion of patients with migraine in the PFO (+) group in the Test Group was significantly higher than the stroke patients in the PFO (-) group (p < 0.05).Conclusions The shunt volume of the PFO is related to ischemic stroke and may be a risk factor for ischemic stroke.