Fifty five patients with ischemic stroke and 15 patients with transient ischemic attacks (TIA) were screened for sleep related breathing disorders (SRBD). Apnea-hypopnea index (AHI) and desaturation index (DI) were analyzed. The clinical status was assessed with National Institute of Health Stroke Scale (NIHSS). The patients with stroke were stratified into groups: without (AHI<or=5), with mild (5<AHI<or=10), and with moderate or severe SRBD (AHI>10). SRBD were present in 36 patients with stroke and in 10 patients with TIA. There were significant differences in the clinical status on admission, as quantified with NIHSS, between stroke patients with mild and moderate or severe SRBD. AHI positively correlated with NIHSS on admission in stroke patients (r=0.54, P<0.01). The final NIHSS score was significantly greater in patients with moderate or severe SRBD than in those with mild SRBD: 3.4+/-1.9 and 1.8+/-1.2, respectively. Our data suggest that the severity of SRBD is related to the clinical status on admission and it influence the clinical outcome after ischemic stroke.