Introduction: Cardiothoracic surgery (CTs) is the most difficult and demanding of all the surgeries that can save lives and enhance quality of life (QoL). Since the end of World War II, cardiothoracic surgery has grown rapidly and seen remarkable technological advancements. The organs of the chest, including the heart, lungs, esophagus, trachea, pleura, mediastinum, chest wall, and diaphragm, are the focus of cardiothoracic surgery. Even though technological advancements have made these complex surgical operations safer and more accessible, there is a considerable chance of serious complications. Preoperative health education is an essential part of the patient's surgical experience, as the primary responsibility of nurses is to prepare patients for surgery by providing health-related information about post-surgical activities. Aim of the study: This study aimed to evaluate the effect of a preoperative therapeutic exercises education program on the clinical outcomes of patients undergoing cardiothoracic surgery through the following: - Through the following specific objectives: 1. Assess the level of knowledge and practice regarding postoperative therapeutic exercises as well as clinical outcomes of patients undergoing CTs. 2. Design and implement a preoperative therapeutic exercises education program for patients undergoing CTs based on previously explored actual needs. 3. Evaluate the effect of the preoperative therapeutic exercises education program on the knowledge and practice regarding postoperative therapeutic exercises as well as the clinical outcomes of patients undergoing CTs. Hypothesis To fulfil the purpose of this study, the following research hypotheses were formulated: H 1: Following the intervention of a preoperative therapeutic exercises education program, the study group patients' level of knowledge and practice of cardiothoracic postoperative therapeutic exercises will differ from that of the control group and improve significantly. H2: The clinical outcomes of patients in the study group following the intervention of a preoperative therapeutic exercises education program will differ significantly from those of the control group. H3: There will be a significant correlation between the clinical outcomes of patients undergoing CTs and their knowledge as well as the practice of postoperative therapeutic exercises. Research Design: A quasi-experimental research design was utilized to conduct the study. 1 Study setting: The present study was conducted in the cardiothoracic surgery departments (males and females wards) of the Cardio-Thoracic Hospital at Zagazig University Hospitals, which is composed of an open-heart ICU that contains 12 beds and cardiothoracic surgery wards that consist of 56 beds. Study Sample: A purposive sample of 60 adults patients who were undergoing cardiothoracic surgery in the aforementioned setting and fulfilled the following inclusion requirements: Male and female adults eighteen years of age and older who are willing to engage and do not have any mental or cognitive impairments. While the exclusion criteria were patients with unstable hemodynamic conditions. The sample was divided into two equal groups, the study group (30 patients) and the control group (30 patients). Tools for data collection: Tool Ι: Patient's assessment interview questionnaire: The researchers adapted it from Vanmathi (2015) to assess patients' knowledge of therapeutic exercises following cardiothoracic surgery and then modified it following a thorough study of relevant literature (Honnalli & Hadapad, 2024; Raghavendran, 2019; Rahul & Reddy, 2017). It was separated into three primary sections, which are as follows: Section I: Patient's demographic characteristics: Ten items of the patients' personal demographic information were covered in this section, including age, gender, marital status, education level, place of residency, occupation, monthly income, smoking, life status, and family support. Section II: Patient's knowledge assessment questionnaire: This section was designed to evaluate the patients' knowledge regarding cardiothoracic postoperative therapeutic exercises. It has thirty items that are separated into two knowledge categories as follows: A. The first section addressed the patients' knowledge about cardiothoracic postoperative therapeutic exercises, which integrated "20 items, B. The second section integrated 10 items that addressed the patient's knowledge about the potential complications of cardiothoracic surgery as a general, the complications that may arise if postoperative therapeutic exercises are not performed. Tool II: Therapeutic exercises observational checklist: This tool was adopted from Craven & Hirnle (2009) and Wilkinson & Van (2007) to assess patients' practice of various cardiothoracic postoperative therapeutic exercises. Tool III: Clinical Outcomes Assessment System: To evaluate the clinical outcomes of cardiothoracic patients postoperatively, researchers adapted this tool from Maarouf & Ameen (2021) following a thorough study of relevant literature (Abdelkader, 2024; Wang et al., 2023; Shahood et al., 2022). Pilot study: Ten percent (six patients) of the primary study sample were used to test the instruments' comprehensiveness, clarity, relevance, comprehension, application, and ease of use. The time required to complete the forms was also estimated with the aid of the pilot study. Patients who took part in the pilot study were included in the formal study sample because no changes were made to the instruments. Field work (1) Assessment phase: - Data collected for this study took place between early July 2023 and December 2023. Over the course of six months, the preoperative therapeutic exercises education program took place. Prior to performing the study. The interviews were conducted during the morning and afternoon shifts on Saturday, Monday, and Wednesday, three days a week, in accordance with the surgical list. 1 (2) The planning phase: - In this phase, the researchers create the therapeutic exercises education program and its booklet about cardiothoracic postoperative exercises in the Arabic language based on the patients' previously determined needs, a review of the most current and pertinent literature, and expert opinions. The theoretical part, which provides to patients detailed knowledge about cardiothoracic surgery (Brief about CTs, The practical part involved training of patients in performing cardiothoracic postoperative therapeutic exercises (3) The implementation phase: - The developed program was implemented in the form of educational sessions carried out in the study settings for the study group patients within their period of hospitalization. The researchers conducted the therapeutic exercises education program over "9" educational sessions, most of which were carried out preoperatively, with three sessions for the theoretical part and six sessions for the practical part. (4) The evaluation phase: - For the purpose of evaluating the effect of the preoperative therapeutic exercises education program on patients undergoing CTs, the studied patients' knowledge, practice, and clinical status were evaluated after (post-phase) the program's intervention using the same data collection tools as the pre-test. The program's effectiveness was assessed by looking at whether there were any changes or differences between the two groups. When the evaluation phase finished, the researchers were given the educational booklet of postoperative therapeutic exercises to control group patients to benefit from it Results: There was a highly statistically significant improvement and difference between the study and control group patients in terms of knowledge, practice, and clinical outcomes. The study group patients had higher levels of overall knowledge and practice regarding CTs postoperative therapeutic exercises (80.0% and 86.7%, respectively) than the control group (46.7% and 43.3%); in addition to having normal or better clinical outcomes of circulatory, respiratory, wound status, and pain level compared to the control group. Conclusion: Rendering to the study results, it can be concluded that The preoperative therapeutic exercises education program is considered an effective nursing strategy for enhancing the clinical outcomes of patients undergoing CTs as it significantly improved the patients' knowledge and practice of cardiothoracic postoperative exercises that in turn improved their clinical outcomes, which reflects its positive effect on patients' outcomes. Recommendation: There should be widespread implementation of the preoperative therapeutic exercises education program in study settings and all comparable ones, including all government hospitals.