To evaluate the usefulness of the examination of the upper airway, paying special attention to the Friedman tongue position (FTP), to confirm obstructive sleep apnea syndrome (OSAS) and its severity. Prospective, single-center, cross-sectional study. Sleep disorders unit of a community hospital. A total of 301 consecutive patients admitted to the sleep disorders unit due to suspicion of OSAS. Assessments included body mass index calculated as weight in kilograms divided by height in meters squared (BMI); neck perimeter measurement; oropharyngeal examination; fiberendoscopy; rhinomanometry; and a sleep study. Apnea-hypopnoea index (AHI), FTP, the uvula size, and certain complementary examinations (sex, age, BMI, cervical perimeter, nasal flow) whose importance has not been clearly established, and to explore their potential value as predictors of the AHI. Findings included the following: the mean (SD) age of the patients was 51 (12) years; 71.1% were male; the mean (SD) BMI was 29.8 (4.6); and the mean (SD) cervical perimeter, 40.5 (3.7) cm. In 94.0% of the patients the AHI value was at least 5.0/hour. Patients with FTP scores of 2 and 3 accounted for 74.1% of the whole cohort: 14.3% had an FTP score of 1, and only 11.6% had a score of 4. Of the 6.0% of cases with a normal AHI, 16 patients were classified as having FTP scores of 1, and 2 as having a score of 2. Tonsil size score (P = .005), uvula score (P = .003), BMI (P < .001), cervical perimeter (P < .001), nasal flow at 150 Pa (P = .02), and age (P = .007) were related to OSAS severity. Curiously, AHI in patients who had undergone tonsillectomy was higher than in the TS1 group (tonsils inside the tonsillar fossa) and quite similar to the TS 2 group (tonsils that extend beyond the tonsillar pillars). In the multiple regression model, only the FTP score showed a relevant relationship to OSAS severity. First, since the FTP score is almost the only parameter related to OSAS severity, a simple oropharyngeal examination can provide key information on this issue. Second, tonsillectomy does not seem to protect against development of OSAS.