Abstract The results of a study using a multivariate statistical approach to determine the effects of a treatment process on the distribution of heavy metals in the soluble fraction of a wastewater sample are reported. Treated, partially treated, and untreated wastewater samples from a municipal treatment plant were analyzed to determine the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn. Analyses were performed by atomic absorption spectrophotometry. The concentration of solids in all samples of wastewater was determined too. Preliminary results show that the primary sedimentation affects the distribution of metals in the soluble fraction more than the secondary sedimentation, and the distribution is not related to the dates of sampling. The results of this study using such analysis may help to determine the optimal conditions as well as to understand the heavy metals removal process trend.