Failures of urban buried gas pipelines have caused significant fire and explosion accidents with tremendous losses. This work presents an advanced two-step approach to analyze failure probabilities of the urban buried gas pipeline. First, a logical failure model is developed with the operational, material and environmental parameters contributing to the failure (Fault Tree Analysis). Second, the logical model is transformed into a network model (Bayesian Network). This novel approach can better reveal the relationships among failure causal factors and can also update the failure probabilities as operational and environmental conditions evolve. The Bayesian network failure model is subsequently applied to a case study. The results indicate that this approach is feasible and reasonable which can assist in identifying safety critical factors. Improving reliability of these safety critical factors can be of great help in enhancing the safety of urban buried gas pipelines. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.