<p>An assessment of currently available cardiovascular magnetic resonance (CMR) methods to quantify aortic (AR) and mitral regurgitation (MR) in a large, population-based setting is lacking. The aim of this study was to evaluate CMR-based AR and MR quantification methods by quantifying AR and MR in participants without valvular heart disease in the population-based Hamburg City Health Study (HCHS). CMR was performed at 3T in the HCHS population. Aortic valve regurgitation volume (CMR-ARV) was directly obtained from 2D transaortic flow measurements. Mitral valve regurgitation volumes (CMR-MRV) were calculated by subtracting aortic forward flow volumes by Flow CMR from left ventricular stroke volumes by Cine CMR as currently recommended and by a method to account for potential confounding effects of AR on MR calculations (CMR-MRV_MOD). Absence of AR and MR were assessed by echocardiography as reference technique. The final CMR study population consisted of 1,874 participants (1,261 without any AR, 1,028 without any MR). Median age of the final study population was 66.0 [58.0, 71.0] years, and 41.1% (<i>n</i> = 770) of participants were female. Median CMR-ARV was 0.7 [0.2, 1.7] ml in participants without any AR. Median CMR-MRV was 9.4 [4.0, 17.0] ml and median CMR-MRV_MOD was 8.7 [4.0, 15.2] ml in participants without any MR, as defined by echocardiography. Unlike accurate, direct ARV measurements by Flow CMR, the currently recommended CMR approach for MRV quantification seems to be affected by a systematic error. MRV measurements by CMR require cautious interpretation, taking into account site specific features.</p>