We undertook this systematic review to determine the prognostic significance of adrenomedullin (ADM) in patients with heart failure and acute myocardial infarction (AMI). Given the difficulty in measuring mature ADM, its surrogate, midregional proadrenomedullin (MRproADM) has been used in most studies. Systematic search of original published studies through MEDLINE and the Cochrane Collaboration databases restricted to reports in English from January 1, 1993, to June 30, 2014, in humans was undertaken. Heterogeneity of studies prohibited a meta-analysis. In patients with heart failure, the area under the curve for prediction of mortality by MRproADM ranged from 0.68 to 0.81 (95% confidence intervals [CI] 0.63 to 0.91) across studies. One nmol/l increase in MRproADM was associated with hazard ratios (HRs) ranging from 1.77 to 2.79 (95% CI 1.29 to 5.95) for death in patients with heart failure. In patients with AMI, the area under the curve for MRproADM predicting MACE ranged from 0.64 to 0.80 (CI 0.51 to 0.87) across studies and death 0.79 to 0.84 (CI 0.73 to 0.90). One nmol/l increase in MRproADM was associated with HR for MACE ranging from 1.78 to 4.10 (CI 1.20 to 10.12), whereas log10 of MRproADM had HRs of 3.63 to 9.75 (CI 1.48 to 26.16) for MACE and 4.86 to 16.68 (CI 4.56 to 60.99) for death across studies in patients with AMI. In conclusion, adrenomedullin is an independent predictor of death in patients with heart failure and of MACE and death in patients who have suffered an AMI. Quantification of this peptide might contribute to improved risk stratification in settings of heart failure and myocardial infarction.