[en] The programme of the International Laboratory of Marine Radioactivity has continued largely along the research lines outlined in the last progress report (IAEA-163). In addition to the regular intercalibration programme of radionuclide measurements, the Laboratory has distributed a number of reference materials for the measurement of trace metals and organochlorine compounds. This latter effort was, and continues to be, supported by the United Nations Environment Programme (UNEP). The first results obtained from the participating laboratories indicate that while comparability for trace element measurements are encouraging, the same cannot be said for the determination of organochlorine compounds. The experience obtained to date in all of the intercalibration exercises attests to the desirability of maintaining such services for the benefit of the scientific community involved in environmental research