Abstract Probabilistic Safety Assessment, usually referred to by the acronym PSA, has by now become a recognized tool for safety analysis of nuclear power plants. In recent years, an increasing number of plants have been analysed, and as the technique has matured, the area of application of PSA based analyses has been expanded. Thus, probabilistic methods are now used increasingly in the day-to-day work concerning the safety, maintenance and operation of plants. In this context, the question of interpretation and application of analysis results in various decision situations has become crucial. This paper gives some comments concerning the basis for decision making involving probabilistic analyses.