The relationship between obstructive sleep apnea (OSA) and adverse cardiovascular outcomes in patients undergoing percutaneous coronary intervention (PCI) remains unclear. We performed a systematic review and meta-analysis to assess the impact of OSA on subsequent cardiovascular events after PCI.We searched the PubMed, EMBASE, and Cochrane library from their inceptions to August 5, 2017. We included cohort studies that described the association between OSA (based on apnea-hypopnea index) and cardiovascular outcomes after PCI with stenting. The primary endpoint was major adverse cardiovascular event (MACE), including all-cause or cardiovascular death, myocardial infarction, stroke, repeat revascularization, or heart failure. Outcomes data were pooled using random effects models and heterogeneity was assessed with the I-2 statistic.We identified 9 studies with 2755 participants. The prevalence of OSA in patients treated with PCI ranged from 35.3% to 61.8%. OSA was associated with increased risk of MACE after PCI (pooled risk ratio [RR] 1.96, 95% confidence interval [CI]: 1.36-2.81, P<.001, I-2=54%). Between-study heterogeneity was partially explained by sample size (2 studies with 100 participants; RR 9.12, 95% CI: 2.69-31.00, I-2=0% vs 7 studies with >100 participants; RR 1.64, 95% CI: 1.23-2.18, I-2=35%). Moreover, the presence of OSA significantly increased the incidence of all-cause death (4 studies), cardiovascular death (4 studies), and repeat revascularization (7 studies) in patients undergoing PCI.Patients with OSA are at greater risk of subsequent cardiovascular events after PCI. Whether treatment of OSA prevents such events warrants further investigation.