Early screening for sleep apnea (SA) is rarely considered in patients with acute cerebral ischemia. We aimed to evaluate the feasibility of early SA screening on a stroke unit, its impact on post-discharge SA care and the relation of SA to clinical features. Patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA) prospectively underwent overnight cardiorespiratory polygraphy within 3 ± 2 days of symptom-onset. Feasibility was defined as analyzable polygraphy in 90 % of studied patients. We enrolled 61 patients (84 % AIS, 16 % TIA): mean age 66 ± 8 years, 44 % men, median NIHSS 1 (0-15), median ESS 5 (0-13). Analyzability was given in 56/61 (91.8 %; one-sided 95 % CI, lower-bound 86.0 %) patients indicating excellent feasibility of early SA screening with no significant differences in stroke severity (100 % in TIA, 91 % minor stroke, 83 % major stroke, p = 0.474). Ninety-one percent (51/56) had an apnea-hypopnea index ≥ 5/h (median: 20/h [0-79]); 32 % (18/56) mild, 30 % (17/56) moderate, and 29 % (16/56) severe SA. When comparing sleep-related ischemic stroke (SIS) and non-SIS patients, no differences were found regarding the presence (95 vs. 89 %, p = 0.49) or severity (e.g., severe SA: 32 vs. 27 %, p = 0.69) of SA. After 12 months, 27/38 (71 %) patients given specific recommendations completed in-laboratory sleep work-up and 7/27 (25 %) were prescribed for non-invasive ventilatory correction. In conclusion, early SA screening is feasible in patients with acute cerebral ischemia and may have a positive impact on post-discharge SA care. Given the high frequency and atypical presentation of SA, early screening for SA should be considered in all acute cerebral ischemia patients.