From December 2010 to June 2011 the mesozooplankton has been sampled at the deep Atlantic, Indian and Pacific Ocean (*). From surface to 3000 m depth a HYDROBIOSS multinet was used distinguishing the epipelagic (77%), mesopelagic (11%) and bathypelagic zones (11%), where five layers were usually sampled (0-200, 200-500, 500-1000, 1000-2000 and 2000-3000 m depth). Among the three oceans, no large differences on abundance were found when taxonomic groups were considered, being always depth the most important factor affecting the vertical zooplankton distribution. The zooplankton abundance strongly decreased with depth and very low abundance was found at deeper waters. Very irregular spatial distribution was observed all across the three oceans, finding the lowest abundance in the south and western Pacific region. Copepods were always the most abundant contributors of the zooplankton community (84%) and more than 260 species identified. They were followed by chaetognaths (5%), siphonophores (3%), ostracods (2%) and euphausiids (1%). In a biogeographical overview, the vertical distribution of the most abundant copepods is analyzed, finding the largest copepods at deeper stratum, where small cosmopolitan copepods were also found
