We present analysis of two-dimensional modeling of the tectonic subsidence in the Ebro Basin along three profiles crossing the Pyrenees, the Ebro Basin, and the Catalan Coastal Range to the east, and the Iberic Cordillera to the west. The deformation of the foreland basin during Tertiary times is simulated using a lighospheric flexure model, incorporating laterally varying elastic thickness. The deflection of the plate is the combined result of Pyrenean loading and the loads exerted by the Iberic Cordillera and Catalan Coastal Range. In the eastern part of the Ebro Basin no extra driving force on the Iberian plate is required. The flexural modeling supports the hypothesis that underplating of the Iberian plate under the European plate is not associated with subduction of old oceanic lithosphere. A good fit with the Tertiary basin subsidence data and Bouguer anomalies is obtained for an elastic plate with local weakness zones under the Ebro Basin. The inferred lateral variation in the elastic rigidity is consistent with heat flow measurements in northern Spain and with major Mesozoic extension in the Iberic Cordillera and Valencia Trough. ¿ American Geophysical Union 1990