In Soil Science standard analysis profiles are obtained, and specialists are interested in evaluating the Soil Quality in view of evident goals, mainly, for this paper, mixtures of agricultural production on it and of forestry and environment. It is difficult and interesting to systematise Soil Quality from profiles. The authors have studied that problem with methods of Mathematical Decision Theory (MDT). MDT presents ways for considering problems of combined fitness or quality for various goals or criteria from profiles or sets of basic known variables, often for decisions on management, finance, machine design, rural development, environment, and projects, that concern future welfare, happiness, or success. Some general considerations are exposed about methods for such application of MDT to that problem, and a case study follows concerning a soil database from Comunidad de Madrid, Spain, consisting in 125 soil profiles that include: colour, texture, pH, permeability, macro- and micro-porosity, slope, field capacity, electric conductivity, CO₃Ca content, organic matter; moreover altitude, annual rain, and temperature regime. A discrete multi-criteria method was applied, in which for each such basic variable an index value was obtained for each soil, directly or indirectly, and a trade-off weight system was elicited to balance all the studied soil characteristics with the aim to establish a comparison among them respectively to quality. The variability in the results in relation to the evaluation systems and disscussed, including the whole case study and these problems with MDT. An appendix could be state of natures depending on distance from Madrid urban centre, on irrigation systems availability and on state-of-art of Agriculture.