Abstract Background: Kidney dysfunction is a strong determinant of prognosis in many settings. Methods: A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included. Results: Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 ml·min·1.73 m−2 was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95–4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22–4.41). An eGFR less than 60 ml·min·1.73 m−2 was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38–1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32–1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml·min·1.73 m−2 the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml·min·1.73 m−2 was 1.62 (95% CI 1.43–1.80), rising to 2.85 (95% CI 2.49–3.27) in patients with an eGFR less than 30 ml·min·1.73 m−2 and 3.75 (95% CI 3.44–4.08) in those with an eGFR less than 15 ml·min·1.73 m−2. Conclusion: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.