Early models of rabbit cardiac fibre structure where from fitting histological fibre orientation onto finite element models. More recently models have been produced using DT-MRI. In a quantitative comparison of these models, in a selected equatorial slice the fibre helix angle has a transmural change of -111.8±30.8º (mean linear fit ± S.D.) in the histological data [H-1]), -92.4±54.5º in DT-MRI dataset [DTI-1] and -86.3±30.7º in DT-MRI dataset [DTI-2]. Variation is large due to outlier data near the RV posterior insertion, and is less when selected anatomical transmural locations are quantified; the lateral LV has a monotonic transmural change of H-1:-87.5±3.7º (mean linear fit ± S.E of slope); DTI-1: -84.8±2.2º; DTI-2:-77.7±2.5º. There is greater variation in the transmural change of the transverse angle than the helix angle (DTI-1, 4.6±83.0º (mean linear fit ± S.D.), pooled data). Limitations in the datasets from both methodologies are discussed in the light of this analysis.