Background: Despite progress in surgery, thoracic surgery continues to be accompanied by complications and is associated with significant rates of postoperative morbidity and readmission to the hospital. Patient education preoperatively is recommended to enhance recovery after surgery enable patients to cope with postoperative pain and anxiety and improve postoperative outcomes. Aim: to evaluate the effect of preoperative teaching sessions on postoperative outcomes among patients undergoing thoracic surgeries. Methods: A quasi-experimental research design was utilized in this study. A Purposive sample of 80 patients aged 18 years or more of both genders who underwent thoracic surgery at the cardiothoracic surgery unit at Mansoura University Hospital, Egypt.  The patients were classified into two equal groups, intervention and control groups, with 40 patients in each group. Tools: three tools were used for data collection; patient assessment sheets, the Modified American Pain Society Patient Outcome Questionnaire (APS-POQ- 1995) & State-Trait Anxiety Inventory. Results: The intervention and control groups showed statistically significant differences in all aspects of post-operative pain management. This included pain severity, functional interference, and affective experiences like anxiety and depression, all with P-values of 0.001. Side effects such as nausea and dizziness also differed significantly (P=0.001). Additionally, the intervention group significantly improved State-Trait Anxiety Inventory scores compared to the control group (P=0.005). Conclusion: Based on results obtained in the current study, the intervention group's postoperative outcomes improved after the implementation of teaching sessions. This improvement was evidenced by enhanced knowledge regarding pain management, encompassing activities, pain severity,  side effects,  affective experience, and perception of the car. Additionally, the intervention group exhibited a reduced level of postoperative anxiety compared to the control group. Recommendations: Planned preoperative teaching should be provided to all patients and their families scheduled for thoracic surgeries as part of standard hospital care preoperatively. Further studies have to be carried out to assess nurse's knowledge and practices regarding care provided for patients  undergoing  thoracic surgeries