Chest physiotherapy considered basic nursing interventions for patients undergoing cardiothoracic surgery to improve breathing efficiency, oxygenation and pulmonary functions. Aim of the study: to evaluate the pulmonary function status after implementing chest physiotherapy for extubated cardiothoracic surgery patients. Design: Quasi experimental research design (study and control) was used in this study. Setting: cardiothoracic intensive care unit and cardiothoracic department at cardiothoracic hospital that belongs to Minia University Hospitals, Egypt. Two tools: 1. Socio demographic and medical Assessment sheet. 2. Oxygenation level assessment sheet. Results: mean age of study and control groups were (38.4±5.4) & (37.2±4.8) year respectively. (40%) from the study group suffered myocardial infarction and did coronary angioplasty, (43.3%) of the control suffered coronary artery stenosis (33.3%) among them did coronary angioplasty. Regarding breathing sound, and pulmonary function test there is statistical significant difference between both groups presented by p value <0.05, also there were significant difference between both groups related to all items of the arterial blood gases test presented by P value with (.031*, .004**, .020*, .013* & .003**). Conclusion: This study concluded that chest physiotherapy had a positive effect on patient's pulmonary function status which reflected on the patients outcomes post cardiothoracic surgery. Recommendations: All cardiac surgery patients should receive an explanation about chest physiotherapy before their operations.