One of the biggest problems in quantitative surface analysis with x-ray photoelectron spectroscopy (XPS) or Auger electron spectroscopy (Am) is in obtaining an accurate measure for the number of photoelectrons or Auger electrons contributing to peaks in spectra. The approach taken for quantitative analysis often depends on the data acquisition method, although there are several subsequent data processing methods that can also be applied. In XPS, spectra are usually acquired by pulse counting, whereas in AES, spectra can be acquired by a variety of methods, e.g. pulse counting, voltage-to-frequency conversion and the use of a variety of modulation techniques. Processing methods involve peak or peak-to-peak height measurement, peak area measurement, background subtraction, deconvolution, differentiation, integration, spectrum addition and subtraction, curve fitting and factor analysis. The application of these techniques to quantitative analysis in XPS and AES will be reviewed.