Objective: Describe and comment on the relationship between some clinical characteristics and respiratory polygraphy results in patients at high risk of obstructive sleep apnea syndrome. Subjects and methods: Cross-sectional descriptive study on 70 patients suspected of having obstructive sleep apnea syndrome at the Central Lung Hospital. Results: 67.1% of patients participating in the study were male, 81.4% were 40 years of age or older, 54.3% were overweight or obese; 78.6% of patients had obstructive sleep apnea syndrome (OSA). The proportion of patients with moderate or severe OSA in the overweight and obese group was greater than in the underweight and normal group (40% vs. 70%), the difference was statistically significant, p=0.01. Conclusion: Overweight and obesity are common in patients with moderate to severe sleep apnea.