Over a number of years the quality of surface water in Poland has been monitored and assessed. Water quality assessments are published every year by specialized institutions. The criteria of assessment used by different regions (voivodships) have not been standardised. The Water Frame Directive has enforced the application of uniform assessment procedures. This directive emphasises mainly the biological quality of water and essentially changes the previous classification methods. In the paper the author has described some aspects of Water Frame Directive, the ways the surface water had been classified over the past 25 years as well the projected aims in this area. ...