Aiming to preserve and protect the environment, physical and chemical quality of young and mature leachate samples from Fez's controlled landfill were studied and assessed. Therefore, leachate samples were taken and analyzed during the period of January - September 2022. The physico-chemical characterization of both young and mature leachates revealed a significant load of organic matter (biological and chemical oxygen demands: BOD5 and COD) and minerals (NTK and PO43-). As well as this, the Metallic Trace Elements (MTEs) concentrations recorded for Cr, Fe, Al and Ni exceeded the threshold levels required in national standards, and their quantitative distribution followed the same pattern at both sites studied: Ni > Fe> Cr > Al > Zn > Pb. The Principal Component Analysis (PCA) enabled us to reduce the database to a smaller dimension by gathering as much information on their trends and correlations. Two components were selected which account for the sum of 64.06% of the factors.