Amazonian soils are heterogeneous. However, few studies have been carried out in the Amazon, mainly because of its considerable size, which complicates the collection of data and the ability to plan for the sustainable use of natural resources. In this study, the physical, chemical and mineralogical attributes of soils in the state of Pará, Brazil, were characterized by examining particle size, fertility, silicon (Si) extracted by sodium hydroxide (NaOH), and iron (Fe), aluminum (Al), and manganese (Mn) extracted by sulfuric acid (H<sub>2</sub>SO<sub>4</sub>), sodium dithionite-citrate-bicarbonate and ammonium oxalate + oxalic acid. Descriptive analysis, multivariate principal component analysis and cluster analysis were carried out. The soils had low concentrations of bioavailable P, Ca<sup>2+</sup>, Mg<sup>2+</sup> and K<sup>+</sup> and high concentrations of Al<sup>3+</sup> and Si and Al oxide contents were higher in Cambisols. Contents of Fe and Mn oxides were higher in both Cambisols and Nitosols, which are rich in oxidic minerals. Multivariate analysis indicated an association between the content of organic carbon and the pH, P, Ca, Mg and K contents. An additional association was observed between clay, potential acidity and the Fe and Al oxide contents.