The results of dosimetric measurements are presented which were performed as part of a German experiment package flown onboard the Russian space station MIR. These results are compared to those of previous missions: the first United States Spacelab mission and the first German Spacelab mission. Detector packages consisting of plastic nuclear track detectors, nuclear emulsions, and thermoluminescence dosimeters were exposed in different sections of the Russian space station. The equivalent dose for the astronauts was calculated from the measurements to be 3.9 mSv. Before and after the flight venous blood was taken from the astronauts. Chromosomal aberrations in peripheral lymphocytes were analyzed. It was found that the radiation exposure during the spaceflight leads to an elevation of dicentric chromosomes, indicating a radiation burden of the astronauts.