1. The existing prevalence estimates of food additive intolerance are being reviewed. 2. In the EEC report the estimated frequency of food additive intolerance is 0.03% to 0.15% based on data from patient groups. 3. The British population study results in a prevalence estimate of 0.026%. The challenged population is 81 children and adults with a history of reproducible clinical symptoms after ingestion of food additives. 4. In the Danish population study a prevalence of 1-2% is found in children age 5-16. In this study a total of 606 children mainly with atopic disease have been challenged. 5. The prevalence estimates vary with a factor 100. As the results vary so do the study populations. 6. If the different study populations are accounted for, a common conclusion can be drawn: Food additive intolerance is found in adults with atopic symptoms from the respiratory tract and skin. The prevalence estimates are questionable but may be less than 0.15%. In adults and children with reproducible, and with more subjective symptoms, such as headache and behavioural/mood change the prevalence is even lower (0.026%). Food additive intolerance is primarily found in atopic children with cutaneous symptoms where the additive is aggravating an existing disease. The prevalence of food additive intolerance in children age 5-16 is 1-2%.