Catastrophic events in recent years have shown that interdependencies between different urban infrastructure systems can result in additional vulnerabilities, such as cascading failure, prolonged downtimes and network congestion. However, currently available simulation models are not able to provide a sufficiently detailed understanding of how these interactions affect the overall resilience of urban infrastructure after disruptive events. This paper presents a novel assessment method that considers interdependencies both at the level of individual infrastructure assets and at the network level. The method uses a stochastic process to simulate the loss and recovery of asset operability taking into account the propagation of failure probabilities and recovery delays due to dependencies on other systems. For the network level, a minimum cost flow assignment model is developed that enables the simulation of coupled flows in interdependent networks. Infrastructure resilience is evaluated as the overall ability of the systems to meet certain demand levels in disruptive event scenarios. A case study analysing the resilience of London’s mass transit and electricity networks against flooding demonstrates the key features of the model and how it could be used to devise more effective strategies for the improvement of urban infrastructure resilience.