The influence of surface roughness on Auger electron spectroscopy (AES) has been investigated by measuring the Auger electron signals from gold films on smooth glass and rough ceramic substrates. The displacement with respect to a defined mean surface level (MSL) of the gold surface on a ceramic substrate was measured by a stylus technique and the surface displacements and surface slopes were shown to be Gaussian distributed. The RMS displacement was 0.28 μm and the RMS slope was 0.38 (φ RMS = 21°). For a sample oriented with its normal parallel to the analyzer axis (CMA or RFA), this surface roughness decreased the detected intensity by ≈10% for normally incident electrons and ≈40% for 20° incident (70° off the analyzer axis) electrons. For the sample oriented with its normal 60° off the analyzer axis, surface roughness decreased the signal ≈20% for either primary beam orientation. A model for the effect of surface roughness on the Auger electron intensities was developed and model calculations exhibited the proper trends with respect to sample and primary beam orientation for smooth and rough surfaces. The intensities calculated for rough surfaces were generally higher than those observed experimentally. The data demonstrate that roughness affects quantitative AES analysis both when absolute intensities are used and when relative intensities are used. The influence of surface roughness on AES has been investigated by comparing the intensity of detected Auger electrons signals from gold films deposited on smooth glass and rough ceramic substrates. The surface roughness was characterized by a stylus technique, by scanning electron microscopy, and by surface replicas examined in a transmission electron microscope. The surface displacement and surface slopes were shown to be Gaussian distributed with an RMS displacement of 0.28 μm and slope of 0.38 (φ RMS = 21°). The effect of surface roughness was calculated by assuming the Auger process could be separated empirically into excitation, E(φ), and detection, D(φ), processes. The relative AE intensities were calculated by integrating E(φ) and D(φ) multiplied by the surface slope distribution, P(φ), over all possible surface slopes. The calculated data showed the proper trends for the effect of varying the primary beam orientation and the sample orientation for the smooth and rough substrates, but the calculated values tended to be ≈10–20% higher than the experimental data for rough surfaces. For the mean surface level (MSL) normal parallel to the analyzer axis, the present surface roughness decreased the AES signal ≈10% for normally incident and ≈40% for 20° incident (70° off the analyzer axis) primary electrons. For the MSL normal oriented 60° off axis, the surface roughness decreased the AES signal ≈20% for both orientations of primary electrons. The effects of surface roughness on quantitative AES are discussed and it is concluded that roughness does affect quantitative analyses regardless of whether that analysis uses absolute peak magnitudes or uses relative (ratio) peak magnitudes.