The provision of fire protection measures in parking buildings is an ongoing debate within the fire protection industry. This article presents a cost-benefit analysis model for the installation of sprinklers for the property protection of these structures. An event tree analysis is used to evaluate vehicle fires in parking buildings drawing on data from New Zealand and international fire statistics. The event tree analysis is then applied to the cost-benefit model in which several scenarios relating to the type of parking building and the availability of sprinklers are considered. A case study is presented for a public parking building with a total floor area of 30,000 m² and the most critical factors in determining the cost-benefit ratio are identified using a Monte-Carlo sensitivity analysis. Using the cost-benefit model and from a building owner's point of view it is found that an economical automatic sprinkler system does not justify itself in a parking building.