A variable-size simplex procedure was used to optimize the overall response of a simultaneous multi-element flame atomic absorption spectrometer. Seven factors (air to fuel ratio, slit width, height above the burner head, and four hollow cathode lamp currents) were optimized for copper, iron, manganese, and zinc atomic absorption. A univariate search procedure was used to determine the effect of individual factors on response. The results of the optimization showed that a comprise set of operating conditions must be used when performing multi-element determinations. The atomic absorption sensitivity of the multi-element determination as compared to single-element determination was reduced by a factor of no more than two.