Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We present a low cost paper-based electronic tongue capable of discriminating forged water samples. System comprises of 4 paper-based potentiometric sensors ( sensitive to Cl -, Na+/ K+, Ca2+/ Mg2+, NO - 3) and a traditional Ag/ AgCl reference electrode. Different electrode materials and methods of insulation were tested with best results obtained for pencil graphite and lamination. The presented electronic tongue was able to distinguish tap and lake water from mineral water samples ( PCA - Principal Component Analysis and KNN - K- nearest neighbour). In total 14 different water samples were used in this study. Sensors presented good signal repeatability, selectivity and reasonable sensitivity.2710 23572362Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Institute of Science and Technology in Bioanalytics (INCTBio)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)