A rapid and simple method for the determination of a series of macroelements (sodium, magnesium, phosphorus, chlorine, potassium, and calcium) and trace elements (manganese, iron, and zinc) by wavelength dispersive X-ray fluorescence has been developed and validated for infant cereal matrices. Reference values were obtained by inductively coupled plasma optical emission spectroscopy and by potentiometry. The 88 investigated samples were commercially available products. Pellets of 4 g were prepared under 10 tonnes of pressure. For each sample, 3 pellets were prepared and analyzed. Limits of quantification and repeatabilities were evaluated. Calibrations were established with 43 samples, and method validation was made using a second set of 45 samples. An evaluation of this alternative method was done by comparison with data obtained from the reference methods. The results show the good performances of the alternative method to routine infant cereals analysis.