This study focuses onto the assessment of the impacts and associated risks posed onto naturalwater bodies by detergent-containing wastewaters in the Prut river basin in North-Eastern Romania. Thefocus of this assessment on detergents as a specific wastewater component is motivated by theenvironmental hazards that detergents cause when entering natural eco-systems, as well as by the rapiddevelopment of the living conditions in the studied area. The assessment of environmental impacts andassociated risks is performed using a methodology that considers risk as a function of risk magnitude(environmental impacts) and the probability of occurrence. The assessment focuses onto four types ofactivities (industry, wastewater treatment plants - WWTPs, municipalities and services) in four counties ofthe Prut River Basin and it is based on surface water quality data that was collected in 2007. The resultshave shown that the highest impacts and associated risks are present in Vaslui and Galati counties (thesouthest part of the Prut river basin) mostly because of the high probabilities that polluting agents wouldexceed the maximum allowed concentrations for detergents.