This trial was conducted to investigate the effect of chest physiotherapy in different positions on the heart and the respiratory system after coronary artery bypass surgery. Patients are divided into two groups of 30 patients each in the study. To the patients in the first group (30 patients), percussion-vibration was performed in the 45 degrees supine position, while slightly laterally lying and endotracheal aspiration was performed in the supine position. To the patients in the second group (30 patients), percussion-vibration was performed in the 00 supine position, while slightly laterally lying and endotracheal aspiration was performed in the supine position. The procedures are repeated two times for all patients and their means were taken. The pre- and post-application values of patients were measured from central venous and arterial catheters and the values of patient monitors were recorded. Comparison of the two groups in terms of respiratory values did not reveal a significant difference, but chest physiotherapy with the head of the bed at 0 degrees was determined to improve cardiac functions. Evaluation of the groups in terms of pre- and postphysiotherapy applications showed a significant increase in mixed venous oxygen saturation in both groups. Chest physiotherapy with the head of the bed elevated to 45 degrees may be recommended in patients who carry a risk of pulmonary complications and who are candidates for chest physiotherapy at an early stage.