There is an increasing trend towards using the concept of risk assessment as an important tool in distribution system asset management. In an ongoing R&D project (RISK DSAM), the main objective is to investigate how information about risk exposure can improve maintenance and reinvestment decisions in an electrical distribution company. As the popularity of Bayesian networks (BN) is increasing, the capacity of this methodology is being explored in the project. The paper presents the BN framework and the link to risk based asset management of electrical distribution systems. Examples are included to illustrate the concept as well as a case study evaluating the risk of failure of an overhead line and its dependence of risk influencing factors such as maintenance intensity and environment.