The compilation of several multibeam data sets unveils for the first time the seafloor of almost the entire northeastern Iberian margin, in the northwestern Mediterranean Basin. This is achieved thanks to an international effort involving mainly Spanish and French research institutions. Submarine canyons, turbiditic channels, landslides and a mid-oceanic valley are the main sedimentary features observed. The size and shape of these features vary throughout the margin. However, the morphometric analysis performed leads to the subdivision of the margin in three main segments: North Catalan Margin (NCM), South Catalan Margin (SCM) and Ebro Margin (EM). We address a non-frequently used scale to tackle the question of which are the main mechanisms controlling the morphological variability between these margins. This is the mesoscale (from one to several hundred kilometres), which allows a comprehensive, holistic and detailed analysis of the seascaping mechanisms shaping the continental margin of northeastern Iberia. Preliminary results suggest that factors controlling the seascape involve a combination of tectonics, long-term fluvial sediment flux to the margin, sediment grain size, basin depth and slope gradient. Modelling of these morphogenetic relationships will contribute to a better knowledge of the seascape development in mid-latitude siliciclastic margins.