BackgroundAlthough cardiac MR and T1 mapping are increasingly used to diagnose diffuse fibrosis based cardiac diseases, studies reporting T1 values in healthy and diseased myocardium, particular in nonischemic cardiomyopathies (NICM) and populations with increased cardiovascular risk, seem contradictory.PurposeTo determine the range of native myocardial T1 value ranges in patients with NICM and populations with increased cardiovascular risk.Study TypeSystemic review and meta‐analysis.PopulationPatients with NICM, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), and patients with myocarditis (MC), iron overload, amyloidosis, Fabry disease, and populations with hypertension (HT), diabetes mellitus (DM), and obesity.Field Strength/Sequence(Shortened) modified Look–Locker inversion‐recovery MR sequence at 1.5 or 3T.AssessmentPubMed and Embase were searched following the PRISMA guidelines.Statistical TestsThe summary of standard mean difference (SMD) between the diseased and a healthy control populations was generated using a random‐effects model in combination with meta‐regression analysis.ResultsThe SMD for HCM, DCM, and MC patients were significantly increased (1.41, 1.48, and 1.96, respectively, P < 0.01) compared with healthy controls. The SMD for HT patients with and without left‐ventricle hypertrophy (LVH) together was significantly increased (0.19, P = 0.04), while for HT patients without LVH the SMD was zero (0.03, P = 0.52). The number of studies on amyloidosis, iron overload, Fabry disease, and HT patients with LVH did not meet the requirement to perform a meta‐analysis. However, most studies reported a significantly increased T1 for amyloidosis and HT patients with LVH and a significant decreased T1 for iron overload and Fabry disease patients.Data ConclusionsNative T1 mapping by using an (Sh)MOLLI sequence can potentially assess myocardial changes in HCM, DCM, MC, iron overload, amyloidosis, and Fabry disease compared to controls. In addition, it can help to diagnose left‐ventricular remodeling in HT patients. Level of Evidence: 2 Technical Efficacy: Stage 3J. Magn. Reson. Imaging 2018;47:891–912.