SUMMARYA gravimetric study has been carried out over a sector of the West Iberian Margin (WIM), constrained by well and seismic data. The analytic development was made through three main stages: the processing of different gravity datasets, the production of gravity anomaly maps and 2,5D models using the processed data, and the geophysical interpretation of maps and models. The final results of the interpretation achieved, allowed the determination of crustal structure and its variation/complexity along the WIM. The main obtained results concern the pre-saline infilling and the deep structure of the margin, which vary related to the location of first-order oblique fractures.