Objectives The objective of this meta-analysis was to assess whether depression in percutaneous coronary intervention (PCI) patients is associated with higher risk of adverse outcomes. Design Systematic review and meta-analysis. Methods EMBASE, PubMed, CINAHL and PsycINFO were searched as data sources. We selected prospective cohort studies evaluating the relationship between depression and any adverse medical outcome, including all-cause mortality, cardiac mortality and non-fatal events, from inception to 28 February 2019. Two reviewers independently extracted information and calculated the risk of cardiovascular events in patients with preoperative or postoperative depression compared with non-depressed patients. Results Eight studies (n=3297) met our inclusion criteria. Most studies found a positive association between depression and adverse cardiovascular outcomes. Meta-analysis yielded an aggregate risk ratio of 1.57 (95% CI 1.28 to 1.92, p<0.0001) for the magnitude of the relation between depression and adverse outcomes. Conclusions Our systematic review and meta-analysis suggests that depression is associated with an increased risk of worse clinical outcome or mortality in patients undergoing PCI. Assessment time and length of follow-up do not have a significant effect on this conclusion. © 2019 Author(s).