In this paper a new approach is presented to predict sulfide formation in sewers based on the IWA Anaerobic Digestion Model No. 1 (ADM1). Compared with existing models the ADM1 has two crucial advantages. Firstly, it simulates anaerobic digestion processes, of which sulfide formation is the final step. Secondly, it uses a more detailed description of the waste water composition. In order to obtain reliable data for calculation an experimental set-up for measuring the Oxygen Uptake Rate (OUR) is used. An implementation of sulfide formation processes into the model matrix is proposed.