The present paper characterizes the variability of bisphenol A, 4-tert-octylphenol and 4-nonylphenol in the phytoplankton of the Gulf of Gdansk. We hypothesized that anthropogenic factors and the properties of phytoplankton, such as the species composition, biomass and volume size, could influence on the increase of EDCs concentrations in phytoplankton in different seasons of the year.