The aim of this study was to determine the clinical features of patients with sleep apnea syndrome (SAS) in the general population. One hundred ten individuals were selected randomly from the census and given hospital appointments. Case histories were taken and complete physical examinations were made. Nighttime respiratory polysomnograms were performed. Twenty-two (20%) of the 110 subjects presented SAS. In the SAS group, 59.1% were habitual snorers and 22.7% reported daytime hypersomnolence. The SAS patients has a mean age of 59.6 +/- 8.8 years and 45.4% showed alterations of the pharynx. No differences in spirometric variables were observed. Only age and daytime hypersomnolence predicted SAS in the multivariate analysis. We conclude that the prevalence of snoring, daytime hypersomnolence, pharyngeal alterations are higher in patients with SAS. The patients are also older. Only age and daytime hypersomnolence predicted of SAS.