The surface topography of various samples has been measured using an optical profiler and a scanning probe microscope (SPM). Optical profilers offer fast and accurate measurements of surface topography but are limited in their lateral resolution by the wavelength of light used. SPMs extend the lateral resolution down to atomic dimensions. Topography measurements are used to obtain surface roughness data. We find that for a scan size of 50 X 50 micrometers , the roughness data obtained from the optical profiler agree with the SPM measurements. The roughness data do not vary significantly when higher magnification images are taken with the SPM on surfaces that lack high frequency components. But for surfaces that have rough features that are smaller than the resolution of the optical profiler, roughness data calculated from higher magnification images by SPM can vary significantly.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.