Background: Sleep-disordered breathing (SDB) is a disease of increasing importance and it is frequent in stroke patients. SDB is being recognized as an independent risk factor for several clinical consequences, including cardiovascular and cerebrovascular disease. Methods: The present review summarizes the current evidence for an independent association between SDB and stroke, defining SDB subgroups, mechanisms, confounding factors and other epidemiological aspects. We analyze stroke outcome and prognosis in SDB patients. A search for recent data on this issue was made in several population-based studies and reference lists of articles. Results: Many recent studies have shown an association between SDB and stroke. Moreover, there is a high prevalence of sleep apnea in patients with stroke. The pathogenesis of stroke in obstructive sleep apnea syndrome is not completely understood and likely to be multifactorial. Several mechanisms like hemodynamic disturbances and inflammatory or endothelial dysfunction could be involved. The presence of SDB in stroke patients may lead to a poor outcome and recurrence. Noninvasive treatments such as continuous positive airway pressure may decrease the risk of stroke in terms of secondary, and possibly, primary prevention. Conclusions: SDB is associated with cerebrovascular morbidity and an unfavorable clinical course. The presence of SDB should be systematically screened in patients with acute stroke. Further studies are needed to determine whether continuous positive airway pressure treatment ameliorates stroke outcome and prognosis.