Introduction: Obstructive sleep apnea (OSA) is a common pulmonary disease. The aim of the study was to evaluate the association between OSA and the prevalence of anxiety and depression. Methods: This is a cross-sectional study. We included patients referred to sleep laboratory. An overnight respiratory polygraphy was performed for all patients. Patients with an AHI<5/h served as controls (non-OSA snorers). Anxiety and depressive were assessed via a self-questionnaire "Hospital Anxiety and Depression Scale (HAD)" in its valid Arabic version. The diagnosis was confirmed for HAD-A and HAD-D scores ? 8. Results: 150 patients were included. The mean age was 54±14 years, with 65.3% females. According to AHI, 108 patients (72%) were diagnosed with OSA (G1) and 42 patients (28%) were considered as non-OSA snorers (G2). The prevalence of anxiety was 44.5% in G1 and 57.1% in G2; the prevalence of depression was 44.5% in G1 and 30.5% in G2. There is no significant difference between the 2 groups concerning the prevalence of anxiety and depression (p=0.2, p=0.4 respectively). Patients with OSA were classified into 3 groups: mild (19.4%), moderate (18.5%) and severe (67.62%). There was no significant difference among the 3 groups concerning the prevalence of anxiety and depression. In the severe group, anxiety and depression in patients treated by CPAP were lower than those untreated (p=0.04 and p=0.01). Factors associated with high prevalence of depression symptoms were female sex, severe untreated OSA, and insomnia. Conclusion: In our study, anxiety and depression are very common in OSA as well as non-OSA snoring patients and they are not associated with the severity of the disease