Obstructive Sleep Apnea (OSA) is associated with accelerated atherosclerosis, cardiovascular and cerebrovascular disease. Carotid artery Intima-Medial Thickness (CIMT) measurement has recently evolved as an important non-invasive diagnostic tool in atherosclerosis. In the current review, we have analysed the association of increased CIMT values with OSA, correlation of increased CIMT with the severity of OSA and the role of CIMT measurement as a prognostic marker in monitoring disease progression and response to therapy. Although some studies in the last few years have tried to address this issue, more randomised controlled trials recruiting larger number of patients are required to define its exact role in regular clinical practice.