Tissue characterization including identification and quantification of fibrosis and oedema plays an important role in many myocardial diseases. Conventionally 2D T1 and T2 maps are acquired sequentially under several breath-holds. However these approaches achieve limited spatial resolution and coverage. Furthermore, partial volume effects at water-fat interfaces may affect T1 and T2 quantification. In this work, we propose a free-breathing high-resolution whole-heart joint T1 and T2 mapping sequence with Dixon encoding which provides co-registered 3D T1 and T2 maps and complementary 3D anatomical water coronary magnetic resonance angiography (CMRA) and fat images in a single scan of ~9min.