Background: The most frequent problems following cardiothoracic surgery are postoperative pulmonary complications (PPCs), which are also the main cause of postoperative morbidity and mortality.  Aim: This study aimed to find out how preoperative respiratory muscle training affected the incidence of PPCs. Materials & Methods: This study included thirty high-risk PPC patients awaiting elective open-heart surgery, ranging in age from 20 to 40 years. They were classified into two main groups: the control group (group I) and the study group (group II). All participants had a pulmonary function test before the study began. On the day before surgery, patients in the control group got standard care. This standard of care included a brief description of the operation's steps, potential risks, side effects, and complications, as well as postoperative chest physiotherapies techniques such as deep breathing exercises, coughing mechanisms, bed mobility, and ambulation. In addition to the usual care provided to the control group, the study group undertook preoperative respiratory muscle training twice daily for at least two weeks before the surgery. Results: However, the findings of the current study noted that preoperative respiratory muscle training reduced the amount of time required for mechanical ventilation, ICU stays, inpatient stays, and overall postoperative hospitalization. Conclusion: Preoperative respiratory muscle training reduced the incidence of pulmonary problems in individuals at high risk for median sternotomy incision.