OBJECTIVES: To investigate the optimal pertussis booster vaccination strategy for the Netherlands and to explore the impact of different assumptions for parameters surrounded by uncertainty. METHODS: The authors designed a realistic age-structured deterministic model. Assuming a steady state situation and correcting for underreporting, the model was calibrated using notification data from the period 1996-2000. Several sensitivity analyses were performed including varying the age of a booster dose (or multiple booster doses), expected vaccine uptake, duration of protection after natural infection, underreporting factors, contact function, and transmission probabilities. RESULTS: The results indicated that the optimal age of an additional booster dose is in the range of 10-15 years, and implementation of this booster dose will reduce both symptomatic and asymptomatic infections, although the incidence of symptomatic infections in the older age classes does increase. The impact of the different assumptions used in the model was in general limited. CONCLUSIONS: We conclude that over a wide range of assumptions, an additional booster dose can reduce the incidence of pertussis in the population.