An investigation of the influence of the aggregate sizes on some elements of an oxisol is presented. Proton Induced X-ray Emission (PIXE) has been used to carry out this analysis. Aggregate sizes from <0.5 mm to 4.7 mm have been used, and results confirm that the presence of Cl and Ca was greater in the small aggregate fractions. The content of K was greater in the large aggregate fractions. Fe, Al, Si, and Ti showed small differences in their concentration as a function of the aggregate sizes.