The relationship between the scaling properties of faulted geological surfaces and parameters describing the underlying fault population are investigated using simulations of a dip-slip faulted surface. Analysis of multiple simulations of sections through the surface allowed the construction of a statistical relationship between the parameters defining the fault population and the fractal dimension of the surface. The results indicate a direct, if complex, relationship between the fault population and the scaling of the surface roughness. The main determining factor is the displacement distribution, with spacing and dip having only a minor contribution. This relationship is tested against examples from the Moray Firth, Scotland, and the central Indian Ocean. ¿ 1999 American Geophysical Union