Objective - To review current knowledge about excess dietary salt as a risk factor for diseases and to compare and discuss the national policies for dietary salt in the Nordic countries. Design - Literature review, questionnaire and interviews. Nordic comparative study. Setting - the Medline bibliographic system and authorities responsible for the national nutritional policies in the Nordic countries. Subjects - Scientific articles published since 1988 concerning the impact of excess dietary salt on health and key persons with responsibilities for the formulation of national recommendations about dietary salt in each of the five Nordic countries. Main outcome measures - Articles dealing with (i) epidemiological observations, (ii) sensitive groups, (iii) underlying biological mechanisms concerning the contents of the latest national recommendations and the wording of legislation and decrees about salt in food-stuffs in the Nordic countries. Results - the impact of excess dietary salt on health mainly concerns hypertension, gastric cancer, osteoporosis and bronchial hyperreactivity. the national policy for dietary salt in Finland differs from the other Nordic countries. in Finland salt is a food additive and a variety of special regulations exist. Finland has chosen a more active way to achieve the existing Nordic recommendation of 5 g salt per day. the daily intake is about 10 g per day in all the Nordic countries. Conclusions - There is need for further epidemiological studies of the relationship between excess dietary salt and gastric cancer, osteoporosis, and bronchial hyperreactivity. the knowledge of the relationship between dietary salt and raised blood pressure is sufficient to put force behind the implementation of existing Nordic recommendations.