Objective The objective of this study was to investigate the effect of preoperative diastolic dysfunction on postoperative mortality and morbidity after cardiovascular surgery. Methods We systematically searched for articles that assessed the prognostic role of diastolic dysfunction on cardiovascular surgery in PubMed, Cochrane Library, Web of Science, Embase, and Scopus until February 2016. Twelve studies (n = 8224) met our inclusion criteria. Because of the scarcity of outcome events, fixed-effects meta-analysis was performed via the Mantel-Haenszel method. Results Preoperative diagnosis of diastolic dysfunction was associated with greater postoperative mortality (odds ratio [OR], 2.41; 95% confidence interval [CI], 1.54-3.71; P < .0001), major adverse cardiac events (OR, 2.07; 95% CI, 1.55-2.78; P ≤ .0001), and prolonged mechanical ventilation (OR, 2.08; 95% CI, 1.04-4.16; P = .04) compared with patients without diastolic dysfunction among patients who underwent cardiovascular surgery. The odds of postoperative myocardial infarction (OR, 1.29; 95% CI, 0.82-2.05; P = .28) and atrial fibrillation (OR, 2.67; 95% CI, 0.49-14.43; P = .25) did not significantly differ between the 2 groups. Severity of preoperative diastolic dysfunction was associated with increased postoperative mortality (OR, 21.22; 95% CI, 3.74-120.33; P = .0006) for Grade 3 diastolic dysfunction compared with patients with normal diastolic function. Inclusion of left ventricular ejection fraction (LVEF) <40% accompanying diastolic dysfunction did not further impact postoperative mortality (P = .27; I2 = 18%) compared with patients with normal LVEF and diastolic dysfunction. Conclusions Presence of preoperative diastolic dysfunction was associated with greater postoperative mortality and major adverse cardiac events, regardless of LVEF. Mortality was significantly greater in grade III diastolic dysfunction.