The research focused on the quantitative performance of infiltration swales on an urban catchment scale. A swale in the city of Utrecht was monitored for 5.5 weeks. Groundwater levels, inflow and outflow were measured. The measured data was used for the validation of a swale model in MetaSwap-Modflow developed for this research. An Infoworks model is used to study the performance of infiltration swales on an urban catchment scale. The research showed that infiltration swales are beneficial on an urban catchment scale. Peak flows and total volume are reduced.