Our purpose was to measure by MRI the quantity and the anatomic distribution of lipid in fish which are of major importance for the quality of the product. This study aimed at validating results from MRI water/fat separation approach by comparing them with MR spectroscopy (MRS) and with chemical analysis. High correlations were found in both cases which confirmed that MRI water/fat separation could be a good alternative for the fat content measurement in fish. Further work will be needed to understand the observed overestimation of MRI compared to chemical analysis. New investigations on a larger set and with more accurate chemical analysis and spectroscopy at higher field should be led in order to better qualify the performance of this technique.