Despite significant progress based on ODP cores obtained during Leg 161 in the Alboran Sea basin, all the tectonic aspects we contemplate in this synthesis paper deserve more extensive investigation by drilling. Deep drilling in the westernmost Mediterranean is undoubtedly the only means of addressing and solving the striking problems raised after the Leg 161 investigations. It seems clear that more detailed structural and geophysical studies of the whole region are needed; undoubtedly, further sampling of the sedimentary cover and acoustic basement in the marine basin is critical. If deeper and safe drilling is feasible in the new perspective of future ODP drilling in the next century (according to the Long Range Plan document), deep drilling (more than 2 km deep) in the West Alboran Basin will provide the unique opportunity to establish a reliable stratigraphy of sediments filling the basin in order to constrain a complete subsidence history of the extended continental crust and to allow for accurate seismic-stratigraphy correlations. Furthermore, concrete lost targets in the East Alboran Basin during Leg 161 because of our inability to go deeper than the base of the Pliocene-Pleistocene sequence at both Sites 977 and 978, as a result of technical drilling problems, merits a further attempt, as we unfortunately missed crucial information on the nature and age of synrift sediments in a key region. We are sure that a transect of deep drill sites to sample the volcanic rocks of the extremely thinned crust in the East Alboran Basin, or even the suspected oceanic crust in the South-Balearic Basin, will probably open innovative perspectives for further investigation. Coordinated studies on the nature of the crust, distribution, and variation of magmatism signatures, and timing of tectonic and thermal subsidence history from the continental to the oceanic crust, should provide clues to the full understanding of lithosphere behavior in driving the evolution of these westernmost Mediterranean basins.