The suitable prediction model for outdoor sound fields depends on the situation and the application. Computationally intensive methods such as parabolic equation methods, FFP methods, and boundary element methods all have advantages in certain situations. These approaches are accurate and predict not only sound pressure levels but also phase information. Such methods are, however, not always able to predict the sound field for more complicated scenarios involving terrain features, atmospheric wind and temperature gradients, and turbulence. Another class of methods is based upon approximate theory—such methods are inherently less accurate but generally faster in computation and may also provide results for complicated scenarios. The accuracy of different approaches in realistic situations is discussed based upon measured and simulated data.