This paper highlights the findings and application of Cochrane reviews and other evidence relevant to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions-medications, surgery, education, nutrition, exercise-and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature. Each article in this PTJ series summarizes a Cochrane review or other scientific evidence resource on a single topic and will present clinical scenarios based on real patients to show how the results of the review can be used to directly inform clinical decisions. This article focuses on the effectiveness of pre-operative physical therapy for elective cardiac surgery. More specifically, does pre-operative physical therapy prevent postoperative pulmonary complications in patients undergoing elective cardiac surgery, and if so, what types of interventions are most effective and are there patients with particular characteristics that benefit from therapy?