Objective: This cross-sectional observational study is designed to evaluate direct effects of obstructive sleep apnea syndrome (OSA) on presence and extent of coronary atherosclerosis by using tomographic coronary calcification scoring on a population asymptomatic for coronary artery disease.Methods: Ninety-seven consecutive patients (49.17±0.86 years) who were evaluated with sleep study for the suspicion of obstructive sleep apnea syndrome underwent tomographic coronary calcium scoring test. Cardiovascular risk factors, current medications and sleep study recordings of all patients were recorded. Patients were classified into 4 groups according to the apnea-hypopnea index (AHI). Linear and logistic regression analyses were used for assessment of association between variables.Results: Coronary risk scores of patients, assessed by tomographic coronary calcium scoring, were observed to increase linearly from simple snoring group to severe OSA groups (p=0.046). When patients were classified according to their gender, AHI and parameters reflecting severity of OSA-related hypoxia were found to correlate significantly with coronary risk scores of women but not with scores of men. Linear regression analysis revealed age as the only independent associated variable with cardiovascular risk scores assessed by tomographic coronary calcification scoring (Beta coefficient: 0.27, 95% CI 0.007-0.087, p=0.018). Binary logistic regression analysis also revealed age as the only variable which independently predicted the presence of coronary calcification (OR:1.11, 95% CI 1.039-1.188, p=0.002).Conclusion: These results suggest that presence of OSA may contribute to coronary artery disease risk of patients in association with its severity; however, association between OSA and subclinical atherosclerosis seems to be primarily dependent on age.