A numerical summary of the water quality of rivers draining into the North Sea from the eastern UK is presented using core information collected within the Land-Ocean Interaction Study (LOIS) and a companion study by the Institute of Hydrology. The analysis is based on weekly monitoring for periods from 1993 to 1999 for major, minor, nutrient, trace and other water quality determinand chemistry. The data cover rivers ranging from the rural Tweed in southeastern Scotland, to the urban and industrially impacted Wear and Humber rivers in the north and central England and two agriculturally impacted rivers in the south of England (Great Ouse and Thames). Within the analysis, monthly averaged concentrations are plotted to show the seasonality. The summary provides specific information on the water quality of UK rivers which is of use in developing European and global initiatives for assessing pollutant inputs to estuarine, coastal and open-sea environments.