In the Gummern quarry it is planned to use the raise-mining system for mining parts of the deposit, which cannot be recovered by the current open-pit mining activities. Therefore general rock mechanical aspects of raise-mining and the stability of the planned underground mining activities are investigated. Raise-mining is in general a variation of stoping systems based on pillars. However, in contrast to these systems stopes of cylindrical shape are mined. Although this special stope geometry and the all side confined pillar system offer from a rock mechanical point of view in comparison to other stoping systems considerable advantages, raise-mining has not been applied so far. As a result there is a lack of experience regarding the design of such a raise-mining system. For this reason important parameters for the design of a raise-mining system are first of all investigated. Basically these parameters are the geometry of the stopes, the central distance between neighbouring stopes, the dimensions of a mining panel, the mining direction inside a mining panel and the width of barrier pillars between mining panels. In a next step the results of these basic investigations are used for determining the stability of the planned raise-mining stopes in the Gummern quarry. Moreover the impact of underground mining on the stability of the nearby pit slope is evaluated. Due to the fact that raise-mining is not applied nowadays, there are any underground mines for in-situ analyses available. For this reason the investigations are mainly based on numerical simulations.