The Skikda region, primarily industrial and agricultural, has experienced significant accelerated industrial and agricultural development over the past decade, resulting in abundant untreated discharges into the physical environment. Our study focused on the physicochemical analysis of the water of the Safsaf River in Skikda. It is based on monitoring three stations during the months of March and August. The aim of this study was to assess the quality of this water and characterize its suitability for agricultural use. To this end, we determined the values of the following physicochemical parameters: Electrical Conductivity (EC), pH, turbidity, total alkalinity (TA), chlorides (Cl-), sodium (Na+), potassium (K+), nitrite (NO2-), ammonium (NH4+), Biological Oxygen Demand (BOD5), and phosphates (PO4-3). The results show that electrical conductivity, sodium, potassium, and chlorides increase downstream of the watershed due to seawater intrusion into the plain. As for the origins of phosphate pollution, whose concentrations have significantly increased along the river, we can explain it by pollution generated by the use of phosphate fertilizers and return irrigation water into surface waters, as well as pollution due to direct input of domestic wastewater.