We present the results of a wide-angle seismic survey conducted over the Chicxulub impact crater. Profile Chicx-A/A1 is a chord across the offshore portion of the crater, and Chicx-B/F is an onshore-offshore profile through the center of the crater. We use travel times recorded by 32 ocean bottom seismograph and 19 land-based receivers to model the crustal structure of the crater. The primary feature in the shallow velocity structure is a low-velocity Tertiary basin, the edge of which correlates with a steep gravity gradient in some regions of our survey. Directly beneath the Tertiary basin at the center of the crater is a region of relatively low velocities and densities that is interpreted as a unit of melt rocks (either suevite breccias with isolated melt pods or suevite breccias overlying a coherent melt sheet). This unit has a thickness of ~1 km and a diameter of ~100 km. Central uplift with a diameter of 40--60 km is observed on Chicx-B/F. A lower limit on the vertical extent of uplift is 9 km. Shallow basement is also observed along the northwest portion of Chicx-B/F, associated with a prominent northwest trending high in the gravity field. Superimposed on a regional trend is Moho uplift of ~1 km near the center of the Chicx-A/A1 profile, with adjacent Moho deepening of ~1.25--1.5 km. The Moho topography may be related to deformation processes associated with the formation of the outer ring or to the excavation and collapse of the transient cavity. ¿ 2001 American Geophysical Union