While wind turbines have beneficial effects for the environment, they inevitably generate environmental noise. In order to protect residents against unacceptable levels of noise, exposure-response relationships are needed to predict the expected percentage of people annoyed or highly annoyed at a given level of wind turbine noise. Exposure-response relationships for wind turbine noise were derived on the basis of available data, using the same method that was previously used to derive relationships for transportation noise and industrial noise. Data from surveys in Sweden and the Netherlands were used to achieve relationships between L den and annoyance, both indoors and outdoors at the dwelling. It is shown that a given percentage of annoyance by wind turbine noise is expected at much lower levels of L den than the same percentage of annoyance by for instance road traffic noise. Results were used to guide new noise regulation for wind turbines in the Netherlands.