With the aim of determining contamination by radioactive materials in the South Adriatic region after May, 1986, activities of 21 radionuclides of natural and artificial origin have been determined by gamma-spectrometry in the samples of sea water, sediments and several characteristic types of organisms collected on several locations in the Boka Kotorska Bay and open sea. Quantitative data on radionuclide contents are presented. Change of activity levels with respect to the “zero state” determined for this region during previous years have also been discussed.