Obstructive sleep apnea syndrome (OSAS) leads to cardiovascular complications such as coronary artery disease, left/right ventricular hypertrophy and dysfunction, heart failure, systemic and pulmonary hypertension, arrhythmias and stroke; and these all cardiovascular complications increase morbidity and mortality of OSAS. However, Cheyne-Stokes respiration, central and obstructive apneas may occur in the patient with heart failure. Increased sympathetic activity by hypoxemia and endothelial dysfunction play a role in cardiovascular complications. Some cardiovascular biomarkers have a role in early diagnosis, treatment and prognosis. In the present review, some cardiovascular biomarkers such as serum C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukins, adiponectin, heart-type fatty acid binding protein (hFABP) and brain (B-type) natriuretic peptide (BNP), and their clinical importance were reviewed.