Preceding the implementation of a Stroke Unit (SU), data have been collected and used for building a simulation model of patient flow. This model was subsequently used to estimate the optimal capacity of the SU to be implemented. Because stroke patients require acute hospital care, this implies a highly variable number of immediate admissions. This variability complicates optimizing the capacity. In order to support decisions with regard to staffing (i.e. capacity) of the SU, different scenarios are simulated and compared to provide insight in the trade-off between regular understaffmg and a low bed occupancy rate. In 1996 the Department of Neurology of the Academic Medical Center in the Netherlands implemented its SU to improve the quality of care for stroke patients. Data collected in the years 1997 and 1998 that the SU has been operational were evaluated and confirm the predictions made from simulating different scenarios. We conclude that simulation models provide a powerful tool for supporting decision making with regard to resource planning at the departmental level in our hospital.