The aim of this paper is to propose a probabilistic method to assess the level of exposure and consequences due to terrorist attacks on electrical substations or other electrical infrastructure assets. The proposed method of inference and simulation allow us to establish a risk-ranking list for the electrical infrastructure assets. The proposed method is based on Bayesian networks, using causality relationship and conditional probabilities to determine the probability of the attacks associated to each one of the substations and to quantify the damage or loss associated to those possible attacks