[en] Even as separate institutes, the EIR (Eidg. Institut fuer Reaktorforschung and the SIN (Schweiz. Institut fuer Nuklearforschung) made use of ionizing radiation and radioactivity in medical diagnosis and therapy. After their fusion into a national laboratory, the Paul Scherrer Institute (PSI), these projects were combined with those of the Radiation Protection Group and the Life Sciences Department was formed. In equality with the departments of Nuclear and Particle Physics, Condensed Matter and Materials Sciences, and Energy Research and Engineering Sciences, the department of Life Sciences is one of the major pillars of the new center. The activities are divided into three areas: radiation medicine, radiopharmacy, and radiation protection. The goal of the first two is to develop social and economic uses of radioactivity and elementary particles. The Division of Radiation Medicine proposes to achieve this through the development of original, dynamic and conformal tumor therapy with charged particles and the Division of Radiopharmacy through the investigation into, and the production of, highly specific diagnostic systems for SPECT, PET and MRI and the investigation of the use of radionuclides in therapy. The third division, Radiation Protection, evaluates the risks of ionizing radiation in biology and the ecosphere and proposes adequate protection measures. The present report describes, in the first section, the outstanding scientific results of the past year and, in the second section, gives a progress report on the on-going programs. It is the first report in this style, but it can be considered as a continuation of the earlier Medical Newsletter of SIN. (author) 59 figs., 19 tabs., 61 refs