Zooplankton community composition, abundance and biomass from two polar localities – Kongsfjorden (Arctic) and Admiralty Bay (Antarctic) is compared. The community composition of zooplankton in both polar regions included similar taxonomic groups and the diversity at the species level was similar. Even though the overall species composition was different, some species were common for both ecosystems, for example Oithona similis, Microcalanus pygmaeus or Eukrohnia hamata. The abundance and biomass of the main zooplankton components (Copepoda) differed greatly between the two ecosystems, both being of an order of magnitude higher in Kongsfjorden than in Admiralty Bay. Kongsfjorden is situated at the border of two regions what induces high productivity with copepods playing an important role, and there is also a strong advection into the fjord. Admiralty Bay is adjacent to the homogenous Antarctic oceanic ecosystem; some advection into the bay occurs as an effect of tide and wind driven processes. Antarctic krill, which was not included in the present study, occupies most of the primary consumers niche and replaces copepods at the second trophic level.