This publication presents biokinetic models and best estimates of biokinetic data for some 120 individual radiopharmaceuticals, giving estimated absorbed doses, including the range of variation to be expected in pathological states, for adults, children and the fetus. Absorbed dose estimates are needed in clinical diagnostic work for judging the risk associated with the use of specific radiopharmaceuticals, both for comparison with the possible benefit of the investigation and to help in giving adequate information to the patient. These estimates provide guidance to ethics committees having to decide upon research projects involving the use of radioactive substances in volunteers who receive no individual benefit from the study. This report supplements current and forthcoming ICRP reports, in particular ICRP Publication 52, Protection of the Patient in Nuclear Medicine.