In Dumas and Svensson (Journal of International Economics 36 (1994) 467) the lifetime of a Krugman (Quarterly Journal of Economics 106 (1991) 669–682) type target zone model is found to be extremely long. This paper shows that the lifetime of the identical target zone regime can be much lower when real disturbances occur. In particular, the mean lifetime is found to be very low when real disturbances occur and the real exchange rate elasticity of the demand for domestic goods is very low. It is also shown that allowing for monetary disturbances to have real effects has very little effect on the lifetime. The results indicate the conditions under which real disturbances might trigger currency crises.