[en] The calculated concentrations of radionuclides in organisms are often obtained by means of bioaccumulation factors (BAF) that describe the internal concentration relative to an external concentration e.g. in the abiotic environments at steady-state conditions. Such factors are often used when modelling the dose to man from radio-nuclides released to the biosphere. Values of bioaccumulation factors vary widely in magnitude among elements, organisms, and environmental conditions which is not always considered. In order to relate the bioaccumulation factors for some radionuclides to environmental conditions as well as to the trophic level of the organism of concern we have compiled an extensive database with bioaccumulation factors (about 5,500 values) together with information on some environmental conditions. The data for nine radionuclides has been extracted and examined. A comparison between the bioaccumulation factors found in this study and values given in literature by IAEA and NCRP shows that the ranges presented in this study are generally somewhat higher with the exception of BAF for molybdenum in freshwater fish which is of the same order of magnitude. This is startling and calls for a thorough research. The amount of readily accessible and reliable values of BAF is limited, often because basic information such as e.g. units and part of organism examined, is not reported. This is surprising and also unfortunate for those who need such data for use in generic or specific models. A major update of recommended values appears to be necessary for many elements to account for the development of analytical methods and experiences from case studies over the past two decades