Non-alcoholic fatty liver disease is associated with obstructive sleep apnea. Abnormalities in liver enzymes can improve following continuous positive airway pressure in patients with obstructive sleep apnea. Computerized tomography can be used to quantify fatty liver changes. We hypothesize that continuous positive airway pressure can reduce morphologic fatty liver changes in patients with obstructive sleep apnea and non-alcoholic fatty liver, an that this reduction can be evident using computerized tomography