A Monte Carlo model is developed to simulate the Xray fluorescence process within a homogeneous multielement mixture. Validation of the model is obtained through comparison of the model's predictions with experimental data for the iron-nickel-chromium system, for which the inter-element effects are severe. The results indicate that the Monte Carlo model is an excellent simulator and may be used in place of a set of standards to determine the influence coefficients for analysis of fluorescence data.