This volume comprises the proceedings of the 5th International Symposium on Shallow Lakes, held at Dalfsen, The Netherlands, in June 2005. The theme of the symposium was Shallow Lakes in a Changing World, and it dealt with water-quality issues, such as changes in lake limnology, especially those driven by eutrophication and pollution, increased nutrient loading and productivity, perennial blooms of cyanobacteria and loss of biodiversity.