In-vivo cardiac diffusion tensor imaging (cDTI) allows imaging of alterations in the cardiac fibre architecture in diseased hearts. In this work, changes in the myocardial microstructure in patients with cardiac amyloidosis were assessed using cDTI and T1 mapping. Mean diffusivity and T1native are significantly increased in the patients and the helical fibre configuration is comparable to healthy controls. There is a trend towards higher/lower MD/FA with increased T1native, respectively. In agreement with T1 mapping, diffusion results support the presence of myocardial degeneration and emphasize the potential of cDTI as contrast agent free tool for characterizing cardiac involvement in amyloidosis patients.