The use of omega-3 fatty acids for diabetic patients is based on well confirmed observations concerning the presence of cardiovascular risk factors in these patients. Changes of lipid metabolism, reduced erythrocyte deformability, increased platelet aggregation, and high blood pressure often found in subjects with diabetes mellitus are all favourably influenced by the administration of eicosapentanoic and docosahexanoic acid. In non insulin dependent subjects, these fatty acids may bring about a rapid reversible deterioration of blood glucose balance while in insulin dependent patients there is no relevant interference. Therefore, omega-3 administration would appear advisable in insulin dependent diabetics with increased cardiovascular risk factors.