The Symposium on Shallow Lakes, held from 23rd-30th, September 1979, at the Biological Research Station, Il Imitz (Austria), was intended to give an insight into current European research on shallow lakes. The reason for the restriction to European participants was firstly to gather as much information as possible on investigations in one geographic area, and secondly the limited time and space available. Since shallow lakes pose a number of problems specifically related to their depth, several symposia have been devoted to this subject. Meetings like the Symposium on the Limnology of Shallow Waters in Tihany (Hungary), in 1973 and the Symposium ‘Flachseeforschung’ in Steinhude (Fed. Rep. of Germany), in 1974 stressed the need for further communication amongst limnologists working in this field. Moreover several international projects, like the OECD-Eutrophication-Program and the Ma B-Project, have included certain aspects of shallow lake limnology. It is hoped by the editors that the proceedings presented here will stimulate further research and a greater exchange of information in this field.