Objectives: The main aim of the study was to assess the effectiveness of deep breathing exercise with incentive Spirometer on the respiratory status of patients who have undergone cardio thoracic and vascular surgery in selected hospitals of Puducherry. Methods: Research design used for the study was quasi experimental one group pre-test post-test design. The study was conducted on 30 patients who have undergone cardio thoracic and vascular surgery at Cardio Thoracic and Vascular wards of Mahatma Gandhi medical College and Research Institute (MGMC&RI), Puducherry and A G Padmavathy hospital, Puducherry. Stratified random sampling technique was used. Data collection tool consisted of demographic variables and assessment of respiratory status using Respiratory Rate, Modified Borg Dyspnea Scale, Peak Flow Meter and Pulseoxymeter. Data were collected by pre assessment questionnaire and observation method. The collected data was tabulated, analyzed and interpreted by using descriptive and inferential statistics. Result: The result showed that deep breathing exercise with incentive spirometer was highly effective among patients who have undergone cardio thoracic and vascular surgery. The obtained P-value 0.000 was highly significant at p <0.001% level. Conclusion: The respiratory complications are the major post-operative complications which reduce the projected outcome of most of the cardio thoracic and vascular surgeries. This study reveals that deep breathing exercise with incentive spirometer can improve the respiratory status of the patients who have undergone cardio thoracic vascular surgery to a great extent.