A retrospective survey of consecutive 480 adult patients (394 men, 96 women, mean age 50.3, SD +/- 10.4 years) with sleep apnea syndrome (SAS) was made in attempt to find out among them the patients with epilepsy. In total 19 subjects (17 men, 2 women, average age 55.8 +/- 8.7 years) representing 4.0% experienced at least two seizures in adult age. The average age at the first seizure was 48.4 +/- 16.1 years. Ten subjects suffered from primarily generalized tonic-clonic seizures, seven from secondarily generalized tonic-clonic seizures, one had complex partial seizures and one simple partial seizures. In 15 subjects (78.9%) the seizures occurred exclusively during sleep. Two patients (11.1%) had seizures exclusively during vigilance and in remaining two subjects the seizures occurred during sleep and vigilance. The findings of high proportion of subjects with epilepsy among SAS subjects, of late seizure onset and of predominantly sleep occurrence of seizures suggest that sleep apnea and hypopnea can facilitate epileptic seizures.