This paper discusses a consistent procedure to quantify geological,  geotechnical and economic risk in tunneling. For an underground excavation a sound rock mass model and a systematic and quantitative rock mass  characterization has to be developed. After defining key parameters, Rock  Mass Types are determined and combined with influencing factors to obtain  the behavior of the rock mass after excavation. A support and excavation  concept is assigned to each Behavior Type, which allows an estimate of time requirement and costs. The  probabilistic processing of distributed input data  allows the determination of probability distributions for time and costs of a tunnel excavation based on the geotechnical risk and the variation of time and costs of different Excavation Classes.