The Porečka River is located in Eastern Serbia and is a right tributary of the Danube. Using data from the Serbian Environmental Protection Agency (SEPA), the paper analyzes water quality using a combined physico-chemical index - Water Pollution Index (WPI). Data for the five year period 2018-2022 were analyzed on Mosna profile. The following parameters were taken into consideration: dissolved O2, O2 saturation, pH, suspended sediments, biological oxygen demand (BOD5), chemical oxygen demand (CODMn), nitrites, ammonium, orthophosphates, metals (Fe, Mn, Ni, Cu, Pb, Cd, Hg), sulphates and coliform germs. The analyzed parameters provide insights into water quality and pollution levels.