This paper applies a macroeconomic-based model for estimating probabilities of default. The first part of the paper focuses on the relation between macroeconomic variables and the default behavior of Dutch firms. A convincing relationship with GDP growth and oil price and, to a lesser extent, the interest and exchange rate exists. The second part of the paper assesses the default behavior based on a stress scenario of two consecutive quarters of zero GDP growth as required by the Basel II framework. It can be concluded that a stress-test scenario covering two quarters of zero GDP growth does not influence the default rate significantly and thus does not seem to be very severe.