This work proposes a new methodology for reliability/availability analysis in power substations. The proposed methodology is based on a combination of Fault Tree Analysis and Monte Carlo Simulations, which are typically used separately in reliability analysis. Results show that vulnerable points can be identified in the substation under analysis, thus providing a useful support when deciding about preventive maintenance schedule or investment direction. The solution here presented is compared to a conventional reliability analysis based on series-parallel networks connection, which allows to verify the effectiveness of this new approach.