Topic of the work presented is the influence of dislocations on the point defect population in semiconductor single crystals. On the one hand, the generation of point defects during plastic deformation of elemental and compound semiconductors is investigated. On the other hand, the influence of the presence of dislocations on the distribution of impurities is dealed with. The connection between the mechanism of dislocation motion and the formation of intrinsic point defects, such as vacancies, interstitials, and antisite defects, is established. Different types of emitted point defects are detected spectroscopically as a function of the deformation parameters. The measured stress- strain curves are discussed with empirical models in order to determine the activation parameters of the dislocation motion in conjunction with the generation of point defects. In addition to the generation of intrinsic point defects during dislocation motion, processes of the aggregation of impurities at dislocations are treated. The extended region with changed material properties around dislocations is connected with the formation of precipitates, as well as with the emission of intrinsic point defects and their reaction to defect complexes.