Obstructive sleep apnoea (OSA) is common in coronary artery disease (CAD) and a possible cause of increased mortality. To date, there is a lack of randomized controlled trials to draw the conclusion that all CAD patients should be investigated for OSA and subsequently be treated with continuous positive airway pressure (CPAP). The Randomized Intervention with CPAP in CAD and OSA (RICCADSA) trial is designed to address if CPAP treatment reduces the combined rate of new revascularization, myocardial infarction, stroke and cardiovascular mortality over a 3-year period in CAD patients with OSA. Secondary outcomes include cardiovascular biomarkers, cardiac function and maximal exercise capacity at 3-month- and 1-year follow-ups. A sample of 400 CAD patients (100 non-sleepy OSA patients randomized to CPAP, 100 to non-CPAP; 100 sleepy OSA patients on CPAP, and 100 CAD patients without OSA) will be included. So far, 240 patients have been enrolled in the trial since December 31, 2005. The RICCADSA trial will contribute to defining the impact of CPAP on prognosis of CAD patients with OSA.