Th is paper describes an application of advanced software tools to the physico- chemical parameters of leached in the sanitary fi lling of Sao Giacomo, located in Caxias do Sul, Brasil. At the beginning, a description of the sanitary fi lling is made, as long as a description of the variables that takes part in the process. An explanation of the missing data is mentioned and the matrixes containing the physico-chemical data are organized to be studied later on. Algorithms of the MPCA type are applied (Multiway Principal Component Analysis) in order to choose the representative fi lling cells for the fi nal analysis; also a PCA algorithm to interpret the correlated variables with the degradation and the biological activity is used. Matlab, InfoStat and Norm software tools were used for the analysis of the multivariate data, to cope with the objective of studying the degradation of organic matter and the biological activity in the sanitary fi lling of Sao Giacomo, at Caxias Do Sul. Th e important parameters to measure biodegradability of organic matter are: pH, ST, alkalinity, dqo, dbo, total nitrogen and ammonia nitrogen. dqo and dbo are parameters which measure biodegradability.