Objectives: The impact of postoperative complications after lung surgery for cancer is substantial, with the increasing age of patients and the presence of comorbidities. This systematic review summarises the effects of Preoperative Exercise Therapy (PET) in patients scheduled for lung surgery on aerobic capacity, physical fitness, postoperative complications, length of hospital stay, quality of life and recovery. Methods: A systematic search on PET prior to lung surgery was conducted. The methodological quality of the included studies was rated using the Physiotherapy Evidence Database (PEDro) scale. The agreement between the reviewers was assessed with Cohen's kappa. Results: A total of eleven studies were included with a methodological quality ranging from poor to good. The agreement between the reviewers, assessed with the Cohen's kappa, was 0.79. Due to substantial heterogeneity in the interventions across the included studies, it was impossible to conduct a meta-analysis. The most important finding of this systematic review was that PET based on moderate to intense exercise in patients scheduled for lung surgery has beneficial effects on aerobic capacity, physical fitness and quality of life. Also PET may reduce postoperative complications and length of hospital stay. Conclusion: PET may have beneficial effects on various physical fitness variables and postoperative complications in patients with lung cancer scheduled for surgery. Future research must focus on developing patient tailored exercise programs and investigate the influence of co-existing comorbidities on the outcome measures. Definitions of PET, including timing, (acceptable) duration, intensity and exercise training methods should be determined and compared.