<b><i>Background:</i></b> Currently, consensus on the effectiveness of incentive spirometry (IS) following cardiac, thoracic, and upper abdominal surgery has been based on randomized controlled trials (RCTs) and systematic reviews of lower methodological quality. To improve the quality of the research and to account for the effects of IS following thoracic surgery, in addition to cardiac and upper abdominal surgery, we performed a meta-analysis with thorough application of the Grading of Recommendations Assessment, Development and Evaluation scoring system and extensive reference to the Cochrane Handbook for Systematic Reviews of Interventions. <b><i>Objective:</i></b> The objective of this study was to determine, with rigorous methodology, whether IS for adult patients (18 years of age or older) undergoing cardiac, thoracic, or upper abdominal surgery significantly reduces30-day post-operative pulmonary complications (PPCs), 30-day mortality, and length of hospital stay (LHS) when compared to other rehabilitation strategies. <b><i>Methods:</i></b> The literature was searched using Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, and Web of Science for RCTs between the databases’ inception and March 2019. A random-effect model was selected to calculate risk ratios (RRs) with 95% confidence intervals (CIs). <b><i>Results:</i></b> Thirty-one RCTs involving 3,776 adults undergoing cardiac, thoracic, or upper abdominal surgery were included. By comparing the use of IS to other chest rehabilitation strategies, we found that IS alone did not significantly reduce 30-day PPCs (RR = 1.00, 95% CI: 0.88–1.13) or 30-day mortality (RR = 0.73, 95% CI: 0.42–1.25). Likewise, there was no difference in LHS (mean difference = −0.17,95% CI: −0.65 to 0.30) between IS and the other rehabilitation strategies. None of the included trials significantly impacted the sensitivity analysis and publication bias was not detected. <b><i>Conclusions:</i></b> This meta-analysis showed that IS alone likely results in little to no reduction in the number of adult patients with PPCs, in mortality, or in the LHS, following cardiac, thoracic, and upper abdominal surgery.