Dynamic ray theory is used to compute the reflection response from a curved surface when the source and receiver are located at the same point. This response has also been computed by Cohen and Bleistein from the Helmholtz formula using the Kirchhoff approximation and the method of multidimensional stationary phase. The same approximation has been derived by Hilterman, and it may also be computed from a simple formula given by Hubral. Ray methods may be applied to the approximate computation of the reflection response from inhomogeneous media with complicated structure. This is not so easily done with methods based on the Kirchhoff approximation of the Helmholtz integral.