Non-crustacean plankton was studied during summer cruises to the northern Norwegian Sea from 1996 to 1998. The dominant species in the investigated area were Aglantha digitale (Hydrozoa) and Sagitta elegans (Chaetognatha). The average density, mean biomass and interannual changes of zooplankton are presented against the background of sea temperatures. The results of this work indicate the very strong inter-annual variability of non-crustacean zooplankton abundance. Correlations with minor changes in sea temperature were noted only for hydromedusae.