A direct method for silicon determination in milk samples by Electrothermal Atomic Absorption Spectrometry was developed. Palladium was used as chemical modifier at a concentration of 610 mg L(-1); with this modifier, silicon was stable up to 1800 degrees C. The precision and accuracy of the method were investigated. The detection limit was 16.2, 2.7 and 7.2 micro g L(-1) for cows' milk, human milk and infant formula, respectively. The method was applied to silicon determination in 17 infant formula samples, 13 human milk samples and 12 cows' milk samples.