This dataset contains microzooplankton abundance data from CTD and Ocean Sampler (OS) deployments during the Marine Productivity programme cruise DI264 to the northern North Atlantic in July - August 2002. Samples from the CTD and from all bottles of the OS were collected and preserved in 10% Lugol's iodine for microzooplankton analysis onshore. All species are placed into size categories and into taxonomic groupings. Abundance and biomass data are included.